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Contents
- 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
Weather in January
January, the same as December, in Portsmouth, Iowa, is a freezing cold winter month, with an average temperature fluctuating between 14.5°F (-9.7°C) and 27.3°F (-2.6°C). In Portsmouth, the lowest average temperatures are observed in January, with a high of 27.3°F (-2.6°C) and a low of 14.5°F (-9.7°C). Weather in January »
Weather in February
February, the last month of the winter in Portsmouth, is another freezing cold month, with an average temperature varying between 31.5°F (-0.3°C) and 18°F (-7.8°C). Portsmouth indicates an average high-temperature of a still subzero cold 31.5°F (-0.3°C) in February, showing minor variation from January's 27.3°F (-2.6°C). Weather in February »
Weather in March
March, the first month of the spring in Portsmouth, is a frosty month, with an average temperature ranging between min 31.8°F (-0.1°C) and max 46.9°F (8.3°C). Portsmouth, Iowa, experiences a clear temperature upsurge in March, with average high-temperatures moving from a subzero cold 31.5°F (-0.3°C) in February to a frosty 46.9°F (8.3°C). Weather in March »
Weather in April
April is a moderate spring month in Portsmouth, Iowa, with an average temperature ranging between max 58.8°F (14.9°C) and min 42.3°F (5.7°C). The shift into April is characterized by a rise in the average high-temperature, transitioning from March's chilly 46.9°F (8.3°C) to a moderate 58.8°F (14.9°C). Weather in April »
Weather in May
The last month of the spring, May, is an agreeable month in Portsmouth, Iowa, with an average temperature varying between 52.9°F (11.6°C) and 69.4°F (20.8°C). The start of May brings a shift in the average high-temperature, increasing from April's refreshing 58.8°F (14.9°C) to an agreeable 69.4°F (20.8°C). Weather in May »
Weather in June
June, the first month of the summer in Portsmouth, is a warm month, with an average temperature ranging between max 79.3°F (26.3°C) and min 63°F (17.2°C). An upsurge in temperatures occurs as May gives way to June, with average highs shifting from an agreeable 69.4°F (20.8°C) to a moderately hot 79.3°F (26.3°C). Weather in June »
Weather in July
July, like June, in Portsmouth, Iowa, is a moderately hot summer month, with an average temperature ranging between min 64.9°F (18.3°C) and max 82.6°F (28.1°C). July registers as the month with the highest average temperatures, reaching 82.6°F (28.1°C) at its peak and 64.9°F (18.3°C) at the lowest. For July, the heat index is computed to be a tropical 89.6°F (32°C). Weather in July »
Weather in August
August, the last month of the summer in Portsmouth, is another warm month, with an average temperature ranging between max 80.2°F (26.8°C) and min 62.1°F (16.7°C). As August takes its course, Portsmouth's average high-temperature registers at a still moderately hot 80.2°F (26.8°C), closely aligning with the preceding month. Weather in August »
Weather in September
The first month of the autumn, September, is still a warm month in Portsmouth, Iowa, with an average temperature ranging between min 55.9°F (13.3°C) and max 75°F (23.9°C). Portsmouth's transition from August to September introduces an average high-temperature of a still warm 75°F (23.9°C), marking an insignificant variation from the 80.2°F (26.8°C). Weather in September »
Weather in October
October, the same as September, in Portsmouth, Iowa, is a moderate autumn month, with an average temperature varying between 44.1°F (6.7°C) and 59.7°F (15.4°C). October is characterized by a clear drop in the average high-temperature, falling from September's warm 75°F (23.9°C) to a mild 59.7°F (15.4°C). Weather in October »
Weather in November
The last month of the autumn, November, is another chilly month in Portsmouth, Iowa, with an average temperature varying between 32.2°F (0.1°C) and 46.2°F (7.9°C). The start of November comes with a reduction in the average high-temperature, receding from a moderate 59.7°F (15.4°C) in October to a chilly 46.2°F (7.9°C). Weather in November »
Weather in December
The first month of the winter, December, is also an icy month in Portsmouth, Iowa, with an average temperature varying between 20.8°F (-6.2°C) and 32.2°F (0.1°C). The arrival of December corresponds with a shift in temperature, down from a frosty 46.2°F (7.9°C) in November to a cold 32.2°F (0.1°C). Weather in December »
Updated: Jun 11, 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 time of year?
January is the month when Portsmouth experiences its coldest temperatures, averaging a high of 27.3°F (-2.6°C) and a low of 14.5°F (-9.7°C).
What is the most humid month?
The most humid month is January, with an average relative humidity of 83%.
What is the driest month?
The month with the least rainfall is January, when the rain falls for 3.2 days and typically collects 0.43" (11mm) of precipitation.
How many days does it rain?
Throughout the year, there are 113.5 rainfall days, and 15.71" (399mm) of precipitation is accumulated.
When does it snow?
Months with snowfall are January through May, October through December.
How much does it snow?
Throughout the year, there are 31.5 snowfall days, and 7.13" (181mm) of snow is accumulated.
What is the month with the least sunshine?
The month with the least sunshine is January, with an average of 4.5h of sunshine.
What is the month with the lowest UV index?
The months with the lowest UV index are January, February, October through December, with an average maximum UV index of 2.
When does it snow the most?
February is the month with the most snowfall. Snow falls for 7.3 days and accumulates 2.09" (53mm) of snow.
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 rainiest month?
The month with the most rainfall is June, when the rain falls for 16.1 days and typically aggregates up to 2.64" (67mm) of precipitation.
When it does not snow?
In Portsmouth, snow does not fall in June through September.
When are the longest days?
With an average of 15h and 6min of daylight, June has the longest days of the year.
What is the month with the highest UV index?
The months with the highest UV index are June through August, with an average maximum UV index of 6.
What are the warmest months?
In Portsmouth, July is known for its average highest temperatures, reaching a high of 82.6°F (28.1°C) and a low of 64.9°F (18.3°C).
What month has the most sunshine?
With an average of 10.4h of sunshine, July has the most sunshine of the year.
What is the least humid month?
October is the least humid month, with an average relative humidity of 68%.
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 in Portsmouth.
Average temperature
Portsmouth, IA
The warmest month (with the highest average high temperature) is July (82.6°F).
The month with the lowest average high temperature is January (27.3°F).
The month with the highest average low temperature is July (64.9°F).
The coldest month (with the lowest average low temperature) is January (14.5°F).
Average pressure
Portsmouth, IA
- Average pressure in January:
30.16"Hg - Average pressure in February:
30.14"Hg - Average pressure in March:
30.06"Hg - Average pressure in April:
29.92"Hg - Average pressure in May:
29.92"Hg - Average pressure in June:
29.87"Hg
- Average pressure in July:
29.95"Hg - Average pressure in August:
29.96"Hg - Average pressure in September:
30"Hg - Average pressure in October:
30"Hg - Average pressure in November:
30.08"Hg - Average pressure in December:
30.13"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.87"Hg).
Average wind speed
Portsmouth, IA
- Average wind speed in January:
10.6mph - Average wind speed in February:
10.6mph - Average wind speed in March:
10.7mph - Average wind speed in April:
10.9mph - Average wind speed in May:
9.3mph - Average wind speed in June:
8.5mph
- Average wind speed in July:
7.2mph - Average wind speed in August:
7.4mph - Average wind speed in September:
8.5mph - Average wind speed in October:
9.7mph - Average wind speed in November:
10.4mph - Average wind speed in December:
10.1mph
The windiest month (with the highest average wind speed) is April (10.9mph).
The calmest month (with the lowest average wind speed) is July (7.2mph).
Average humidity
Portsmouth, IA
The month with the highest relative humidity is January (83%).
The month with the lowest relative humidity is October (68%).
Average rainfall
Portsmouth, IA
- Average rainfall in January:
0.43" - Average rainfall in February:
0.47" - Average rainfall in March:
0.91" - Average rainfall in April:
1.26" - Average rainfall in May:
2.6" - Average rainfall in June:
2.64"
- Average rainfall in July:
1.5" - Average rainfall in August:
1.93" - Average rainfall in September:
1.65" - Average rainfall in October:
1.06" - Average rainfall in November:
0.55" - Average rainfall in December:
0.71"
The wettest month (with the highest rainfall) is June (2.64").
The driest month (with the least rainfall) is January (0.43").
Average rainfall days
Portsmouth, IA
- Average rainfall days in January:
3.2 days - Average rainfall days in February:
2.8 days - Average rainfall days in March:
8.8 days - Average rainfall days in April:
12.8 days - Average rainfall days in May:
15.7 days - Average rainfall days in June:
16.1 days
- Average rainfall days in July:
13.1 days - Average rainfall days in August:
12.3 days - Average rainfall days in September:
10.5 days - Average rainfall days in October:
8.5 days - Average rainfall days in November:
5.5 days - Average rainfall days in December:
4.2 days
The month with the highest number of rainy days is June (16.1 days).
The month with the least rainy days is February (2.8 days).
Average snowfall
Portsmouth, IA
- Average snowfall in January:
1.57" - Average snowfall in February:
2.09" - Average snowfall in March:
1.22" - Average snowfall in April:
0.28" - Average snowfall in May:
0.16" - Average snowfall in June:
0"
The month with the highest snowfall is February (2.09").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days
Portsmouth, IA
- Average snowfall days in January:
8.3 days - Average snowfall days in February:
7.3 days - Average snowfall days in March:
4.8 days - Average snowfall days in April:
1 days - Average snowfall days in May:
0.3 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:
0.7 days - Average snowfall days in November:
3 days - Average snowfall days in December:
6.1 days
The month with the highest number of snowfall days is January (8.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight / Average sunshine
Portsmouth, 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 6min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in January:
4h and 3min - Average sunshine in February:
5h and 1min - Average sunshine in March:
6h and 2min - Average sunshine in April:
8h and 1min - Average sunshine in May:
8h and 5min - Average sunshine in June:
9h and 5min
- Average sunshine in July:
10h and 2min - Average sunshine in August:
9h and 5min - Average sunshine in September:
9h and 1min - Average sunshine in October:
5h and 5min - Average sunshine in November:
5h and 5min - Average sunshine in December:
4h and 5min
The month with the most sunshine is July (Average sunshine: 10h and 24min).
The month with the least sunshine is January (Average sunshine: 4h and 30min).
Average sunshine days
Portsmouth, IA
- Average sunshine days in January:
20.1 days - Average sunshine days in February:
17.8 days - Average sunshine days in March:
17.9 days - Average sunshine days in April:
15 days - Average sunshine days in May:
12.8 days - Average sunshine days in June:
11.4 days
- Average sunshine days in July:
12.7 days - Average sunshine days in August:
15.5 days - Average sunshine days in September:
16.5 days - Average sunshine days in October:
20.5 days - Average sunshine days in November:
21.3 days - Average sunshine days in December:
21.6 days
The month with the most sunshine days is December (21.6 days).
The month with the least sunshine days is June (11.4 days).
Average UV index
Portsmouth, IA
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, October, November and December (UV index 2).
Average cloud cover
Portsmouth, IA
The month with the most cloud cover is January (Cloud cover 52).
The month with the least cloud cover is July (Cloud cover 27).
Average visibility
Portsmouth, IA
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Portsmouth, Iowa, USA
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