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Contents
- The climate of Iowa City
- The best time to visit Iowa City
- The worst time to visit Iowa City
- Spring weather in Iowa City
- Summer weather in Iowa City
- Autumn weather in Iowa City
- Winter weather in Iowa City
- Weather in January
- Weather in February
- Weather in March
- Weather in April
- Weather in May
- Weather in June
- Weather in July
- Weather in August
- Weather in September
- Weather in October
- Weather in November
- Weather in December
- Frequently asked questions
- Average temperature
- Average pressure
- Average wind speed
- Average humidity
- Average rainfall
- Average rainfall days
- Average snowfall
- Average snowfall days
- Average daylight
- Average sunshine
- Average sunshine days
- Average UV index
- Average cloud cover
- Average visibility
Golden and brown trees in a scenic, neat lawn near the mighty grandeur of the Old Capitol building, Iowa City
The climate of Iowa City
Climate conditions in Iowa City illustrate a pattern typical of the Köppen Dfa classification, also known as the Humid continental climate group - hot summer type. Its geographical positioning in the Midwest region of the United States accounts for this.
Monthly average temperatures fluctuate noticeably, reaching a maximum in July of 81.5°F (27.5°C) and dipping to a low point in January of 15.3°F (-9.3°C). The prevalence of humidity is also notable, with yearly average relative humidity ranging from a low of 72% in October to a high of 83% in both January and July.
Rainfall patterns somewhat correlate with the warmer months of the year, with the highest average precipitation occurring in May. Snowfall occurs from November to April, with January and February being the snowiest months.
This city is known to experience seasons in full form. Summers are warm and humid, winters are frigid and can be somewhat snowy, while spring and autumn offer a moderate transition between the extremes.
Monthly average temperatures fluctuate noticeably, reaching a maximum in July of 81.5°F (27.5°C) and dipping to a low point in January of 15.3°F (-9.3°C). The prevalence of humidity is also notable, with yearly average relative humidity ranging from a low of 72% in October to a high of 83% in both January and July.
Rainfall patterns somewhat correlate with the warmer months of the year, with the highest average precipitation occurring in May. Snowfall occurs from November to April, with January and February being the snowiest months.
This city is known to experience seasons in full form. Summers are warm and humid, winters are frigid and can be somewhat snowy, while spring and autumn offer a moderate transition between the extremes.
The best time to visit Iowa City
The finest time to visit Iowa City would arguably be from late spring to early summer (from mid-May to June), when temperatures are pleasant, rainfall is still acceptable, and the city's outdoor activities are in full swing. The average high temperature in May is 69.8°F (21°C), and it increases to 79.2°F (26.2°C) in June. Sunshine hours are also at their peak during this period, offering visitors abundant daylight to enjoy the city’s attractions.
The worst time to visit Iowa City
Visiting Iowa City in the winters may pose some challenges to potential visitors not accustomed to intense cold and considerable snowfall. January typically records the lowest temperatures, with an average high of 27.3°F (-2.6°C) and a low of 15.3°F (-9.3°C). Snowfall is most probable during this period, coupled with diminished sunlight hours, reducing outdoor recreational prospects.
Spring weather in Iowa City
Spring in Iowa City usually begins mild and progressively warms. Temperatures start from a high of 46.6°F (8.1°C) in March and steadily increase to 69.8°F (21°C) by May. A gradual decrease in relative humidity, from 75% in March to 78% in May, couples this increment, alongside the sharp rise in average rainfall from 2.09in in March to 4.69in in May. Spring also signals the end of the snowfall season.
Summer weather in Iowa City
Summer in Iowa City is characterized by a humid continental climate, with temperatures reaching peaks between June and August. The hottest month, July, experiences an average high temperature of 81.5°F (27.5°C) and a low of 64.6°F (18.1°C). Precipitation rates do not vary significantly during these months, and there is no snowfall. The number of sunshine hours is the highest in this phase, with an average of 15.2 hours per day in June.
Autumn weather in Iowa City
Autumn in Iowa City experiences a noticeable temperature drop from September through November. However, it also presents a balance between the extremes of summer and winter. September begins with a warm 75.2°F (24°C) high that drops to a much cooler 46.4°F (8°C) by November. Rainfall starts to decrease, but November does see the return of snowfall after a long hiatus.
Winter weather in Iowa City
Winter in Iowa City is characterized by significantly lower temperatures, increased snowfall, and smaller amounts of daylight. In December, the high averages at 34°F (1.1°C) and continues to drop to a low of 27.3°F (-2.6°C) by January. Snowfall begins as early as November but truly peaks in January with an average of 5.28in. The daylight hours dwindle during these months, making the days feel even colder.
Weather in January
January in Iowa City presents the coldest conditions of the year. Freezing temperatures persist throughout the day with the highest reading a mere 27.3°F (-2.6°C) and dipping as low as 15.3°F (-9.3°C). Snowfall often blankets the city, accompanied by chilly winds. Weather in January »
Weather in February
A slight increase in temperature signifies the start of February. However, the weather remains well below freezing with snow occasionally adding a fresh layer to the winter landscape. Wind speeds remain high, amplifying the felt chilliness. Weather in February »
Weather in March
March ushers in the first breath of spring in Iowa City, with snowfall giving way to 2.09" (53mm) of rainfall. Temperatures start ascending from the frosty realms, nevertheless, frost still retains its grip during the nights. The increasingly longer daylight hours begin to breathe warmth back into the cityscape. Weather in March »
Weather in April
In April, the transition from winter to spring becomes more pronounced. An increase in temperature, wind speed, and daylight hours collectively usher in a more hospitable weather pattern. Rainfall becomes a dominant feature, replacing snowfall, and nurturing the burgeoning plant life. Weather in April »
Weather in May
May signifies the definitive arrival of spring in Iowa City. The city receives generous rainfall of 4.69" (119mm) which facilitates lush growth in parks and gardens. Temperatures gather momentum towards the imminent summer, and residents can now frequently venture outdoors without heavy winter clothing. Weather in May »
Weather in June
Summer introduces itself gently in June. Temperatures remain comfortable, and the city enjoys an ample amount of daylight, reaching up to 15.2 hours per day. Though rainfall is still considerable, it lessens slightly, allowing more frequent sunny spells. Weather in June »
Weather in July
July stands as the warmest month of the year, with temperatures soaring to an average high of 81.5°F (27.5°C). However, humidity levels also spike, providing a hint of stickiness to the hot summer days. Picnics, outdoor sporting events, and other social gatherings are predominantly held during the long, sunny days. Weather in July »
Weather in August
August witnesses a slight drop in temperature, though the weather continues to stay firmly within the summer category. Residents enjoy moderate balance between warmth and rainfall, thereby fostering enticing days for outdoor recreation. Weather in August »
Weather in September
September signals the arrival of fall in Iowa City. The highest temperature drops to a comfortable 75.2°F (24°C) while the lower end stays comfortably above freezing. Emerald green leaves slowly acquire warm, russet hues as daylight hours begin to shorten. Weather in September »
Weather in October
The trend of falling temperatures continues in October, ending in an average low of 45°F (7.2°C) by the month’s end. Winter coats, scarves, and hats slowly start replacing light fall wear, making their first appearances after the summer hiatus. Weather in October »
Weather in November
November in Iowa City is characterized by an unmistakable chill in the air, hinting towards the imminent winter. The rare phenomenon of snowfall can make an early appearance, adding to the frosty ambiance. As daylight hours grow shorter, the city's residents retreat indoors, preparing for the onset of the long winter season. The average high-temperature decreases in November, shifting from a refreshing 60.4°F (15.8°C) in October to a frosty 46.4°F (8°C). Weather in November »
Weather in December
December ushers in the winter season, with temperatures dipping well below freezing, particularly at night, reaching lows of 22.8°F (-5.1°C). Snowfall becomes frequent, contributing to a thick white blanket enveloping the city. Weather in December »
Updated: Jul 15, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the coldest month?
January stands out as Iowa City's coldest month, with temperatures ranging between an average high of 27.3°F (-2.6°C) and a low of 15.3°F (-9.3°C).
What is the most humid month?
The months with the highest humidity are January and July, with an average relative humidity of 83%.
What is the driest month?
The months with the least rainfall are January and February Rain falls for 5.7 days and accumulates 1.34" (34mm) of rain.
How much does it rain?
In Iowa City, during the entire year, the rain falls for 140.4 days and collects up to 29.57" (751mm) of precipitation.
When does it snow in Iowa City?
Months with snowfall are January through April, October through December.
When does it snow the most?
The month with the most snowfall is January, when snow falls for 10.9 days and typically aggregates up to 5.28" (134mm) of snow.
How many days does it snow?
In Iowa City, during the entire year, snow falls for 37.7 days and aggregates up to 16.42" (417mm) of snow.
What is the month with the least sunshine?
January has the least sunshine of the year in Iowa City, with an average of 4.2h of sunshine.
What is the month with the lowest UV index?
With an average maximum UV index of 1, January is the month with the lowest UV index.
When is Daylight Saving Time (DST)?
On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts, and the time zone changes from CST to CDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from CDT to CST.
What is the wettest month?
May is the month with the most rainfall in Iowa City. Rain falls for 18.4 days and accumulates 4.69" (119mm) of precipitation.
When it does not snow?
May through September are months without snowfall.
When are the longest days?
The month with the longest days is June, with an average of 15h and 12min of daylight.
When is the highest UV index?
The months with the highest UV index are June and July, with an average maximum UV index of 6.
What month is the hottest?
Iowa City's July weather, with an average high temperature of 81.5°F (27.5°C) and an average low temperature of 64.6°F (18.1°C), tends to be the warmest of the year.
What month has the most sunshine?
With an average of 10h of sunshine, July has the most sunshine of the year.
What is the least humid month?
With an average relative humidity of 72%, October is the least humid month.
What is the month with the shortest days?
With an average of 9h and 12min of daylight, December has the shortest days of the year.
Average temperature
Iowa City, IA
The warmest month (with the highest average high temperature) is July (81.5°F).
The month with the lowest average high temperature is January (27.3°F).
The month with the highest average low temperature is July (64.6°F).
The coldest month (with the lowest average low temperature) is January (15.3°F).
Average pressure
Iowa City, IA
- Average pressure in January:
30.14"Hg - Average pressure in February:
30.12"Hg - Average pressure in March:
30.08"Hg - Average pressure in April:
29.93"Hg - Average pressure in May:
29.94"Hg - Average pressure in June:
29.9"Hg
- Average pressure in July:
29.96"Hg - Average pressure in August:
29.97"Hg - Average pressure in September:
30.02"Hg - Average pressure in October:
30.01"Hg - Average pressure in November:
30.09"Hg - Average pressure in December:
30.11"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).
Average wind speed
Iowa City, IA
- Average wind speed in January:
10.4mph - Average wind speed in February:
10.4mph - Average wind speed in March:
10.4mph - Average wind speed in April:
10.7mph - Average wind speed in May:
9mph - Average wind speed in June:
7.9mph
- Average wind speed in July:
6.9mph - Average wind speed in August:
6.9mph - Average wind speed in September:
8mph - Average wind speed in October:
9.6mph - Average wind speed in November:
10.3mph - Average wind speed in December:
9.9mph
The windiest month (with the highest average wind speed) is April (10.7mph).
The calmest months (with the lowest average wind speed) are July and August (6.9mph).
Average humidity
Iowa City, IA
The months with the highest relative humidity are January and July (83%).
The month with the lowest relative humidity is October (72%).
Average rainfall
Iowa City, IA
- Average rainfall in January:
1.34" - Average rainfall in February:
1.34" - Average rainfall in March:
2.09" - Average rainfall in April:
3.19" - Average rainfall in May:
4.69" - Average rainfall in June:
3.9"
- Average rainfall in July:
3.03" - Average rainfall in August:
1.93" - Average rainfall in September:
2.44" - Average rainfall in October:
2.48" - Average rainfall in November:
1.69" - Average rainfall in December:
1.46"
The wettest month (with the highest rainfall) is May (4.69").
The driest months (with the least rainfall) are January and February (1.34").
Average rainfall days
Iowa City, IA
- Average rainfall days in January:
5.7 days - Average rainfall days in February:
5 days - Average rainfall days in March:
11.5 days - Average rainfall days in April:
15.3 days - Average rainfall days in May:
18.4 days - Average rainfall days in June:
17.7 days
- Average rainfall days in July:
15.2 days - Average rainfall days in August:
12.8 days - Average rainfall days in September:
12 days - Average rainfall days in October:
11.5 days - Average rainfall days in November:
8.3 days - Average rainfall days in December:
7 days
The month with the highest number of rainy days is May (18.4 days).
The month with the least rainy days is February (5 days).
Average snowfall
Iowa City, IA
The month with the highest snowfall is January (5.28").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days
Iowa City, IA
- Average snowfall days in January:
10.9 days - Average snowfall days in February:
9.4 days - Average snowfall days in March:
4.9 days - Average snowfall days in April:
1.3 days - Average snowfall days in May:
0 days - Average snowfall days in June:
0 days
- Average snowfall days in July:
0 days - Average snowfall days in August:
0 days - Average snowfall days in September:
0 days - Average snowfall days in October:
0.5 days - Average snowfall days in November:
2.3 days - Average snowfall days in December:
8.4 days
The month with the highest number of snowfall days is January (10.9 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight / Average sunshine
Iowa City, IA
- Average daylight in January:
9h and 4min - Average daylight in February:
10h and 4min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 2min - Average daylight in May:
14h and 4min - Average daylight in June:
15h and 1min
- Average daylight in July:
14h and 5min - Average daylight in August:
13h and 5min - Average daylight in September:
12h and 3min - Average daylight in October:
11h and 1min - Average daylight in November:
9h and 5min - Average daylight in December:
9h and 1min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in January:
4h and 1min - Average sunshine in February:
4h and 2min - Average sunshine in March:
6h and 3min - Average sunshine in April:
7h and 5min - Average sunshine in May:
8h and 4min - Average sunshine in June:
9h and 4min
- Average sunshine in July:
10h and 0min - Average sunshine in August:
9h and 5min - Average sunshine in September:
9h and 2min - Average sunshine in October:
5h and 3min - Average sunshine in November:
5h and 2min - Average sunshine in December:
4h and 2min
The month with the most sunshine is July (Average sunshine: 10h and 0min).
The month with the least sunshine is January (Average sunshine: 4h and 12min).
Average sunshine days
Iowa City, IA
- Average sunshine days in January:
16.3 days - Average sunshine days in February:
15 days - Average sunshine days in March:
14.6 days - Average sunshine days in April:
12.8 days - Average sunshine days in May:
10 days - Average sunshine days in June:
10.1 days
- Average sunshine days in July:
12.2 days - Average sunshine days in August:
15.8 days - Average sunshine days in September:
17.1 days - Average sunshine days in October:
17.9 days - Average sunshine days in November:
18.5 days - Average sunshine days in December:
17 days
The month with the most sunshine days is November (18.5 days).
The month with the least sunshine days is May (10 days).
Average UV index
Iowa City, IA
The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover
Iowa City, IA
The month with the most cloud cover is January (Cloud cover 56).
The month with the least cloud cover is August (Cloud cover 29).
Average visibility
Iowa City, IA
The months with the highest visibility are January, February, March, April, May, June, August, September, October, November and December (6mi).
The month with the lowest visibility is July (5mi).
Iowa City, Iowa, USA
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