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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, like December, is a freezing cold winter month in Harvey, Illinois, with an average temperature ranging between max 29.7°F (-1.3°C) and min 18.9°F (-7.3°C). The coldest month is January, with an average high-temperature of 29.7°F (-1.3°C) and an average low-temperature of 18.9°F (-7.3°C). Weather in January »
Weather in February
The last month of the winter, February, is an icy month in Harvey, Illinois, with an average temperature ranging between max 33.1°F (0.6°C) and min 21.2°F (-6°C). The start of February marks an average high-temperature of an icy 33.1°F (0.6°C), hardly distinguishable from the conditions in January. Weather in February »
Weather in March
The first month of the spring, March, is a frosty month in Harvey, Illinois, with temperature in the range of an average low of 32.4°F (0.2°C) and an average high of 45.5°F (7.5°C). With the onset of March, Harvey's average high-temperature experiences a rise, moving from February's wintry 33.1°F (0.6°C) to a chilly 45.5°F (7.5°C). Weather in March »
Weather in April
April in Harvey, Illinois, is a mild spring month, with an average temperature ranging between min 41.7°F (5.4°C) and max 56.7°F (13.7°C). April's arrival sees a rise in the average high-temperature, jumping from March's frosty 45.5°F (7.5°C) to a mild 56.7°F (13.7°C). Weather in April »
Weather in May
The last month of the spring, May, is a pleasant month in Harvey, Illinois, with an average temperature ranging between max 68.7°F (20.4°C) and min 52.3°F (11.3°C). Entering May, Harvey sees a temperature rise, with the average high-temperature advancing from April's moderate 56.7°F (13.7°C) to a pleasant 68.7°F (20.4°C). Weather in May »
Weather in June
June, the first month of the summer in Harvey, is a warm month, with an average temperature varying between 77.7°F (25.4°C) and 61.7°F (16.5°C). Harvey in June shows a temperature shift, moving from an average high of a pleasant 68.7°F (20.4°C) in May to a moderately hot 77.7°F (25.4°C). Weather in June »
Weather in July
July, like June, in Harvey, Illinois, is a moderately hot summer month, with an average temperature ranging between min 65.8°F (18.8°C) and max 81.3°F (27.4°C). Temperature readings reach their annual highs in July, averaging 81.3°F (27.4°C) and a minimum average of 65.8°F (18.8°C). The heat index for July is computed to be a hot 87.8°F (31°C). Weather in July »
Weather in August
August, the last month of the summer in Harvey, is another warm month, with temperature in the range of an average high of 80.1°F (26.7°C) and an average low of 64.6°F (18.1°C). As Harvey welcomes August, the average high-temperature stabilizes at a still moderately hot 80.1°F (26.7°C), showing little deviation from July's 81.3°F (27.4°C). Weather in August »
Weather in September
The first month of the autumn, September, is still a warm month in Harvey, Illinois, with an average temperature varying between 58.3°F (14.6°C) and 73.9°F (23.3°C). Harvey's September weather shows a modest shift in high-temperatures, falling from August's 80.1°F (26.7°C) to a still warm 73.9°F (23.3°C). Weather in September »
Weather in October
October, the same as September, is another comfortable autumn month in Harvey, Illinois, with an average temperature varying between 46.9°F (8.3°C) and 61.2°F (16.2°C). The beginning of October involves a decrease in the average high-temperature, transitioning from a moderately hot 73.9°F (23.3°C) in September to a refreshing 61.2°F (16.2°C). Weather in October »
Weather in November
The last month of the autumn, November, is another chilly month in Harvey, Illinois, with an average temperature fluctuating between 46.9°F (8.3°C) and 34.9°F (1.6°C). The beginning of November marks a decrease in the average high-temperature, transitioning from a refreshing 61.2°F (16.2°C) in October to a frosty 46.9°F (8.3°C). Weather in November »
Weather in December
The first month of the winter, December, is still a cold month in Harvey, Illinois, with an average temperature varying between 25.9°F (-3.4°C) and 35.6°F (2°C). The onset of December coincides with a reduction in the average high-temperature, falling from a frosty 46.9°F (8.3°C) in November to a wintry 35.6°F (2°C). Weather in December »
Updated: Aug 10, 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?
Temperature readings reach their annual highs in January, averaging 29.7°F (-1.3°C) and a minimum average of 18.9°F (-7.3°C).
What is the most humid month?
January and February, with an average relative humidity of 82%, are most humid months.
How much does it rain in Harvey?
Throughout the year, there are 155.6 rainfall days, and 31.3" (795mm) of precipitation is accumulated.
When does it snow?
Months with snowfall are January through April, October through December.
What is the snowiest month?
January is the month with the most snowfall. Snow falls for 12.6 days and accumulates 4.53" (115mm) of snow.
How many days does it snow?
In Harvey, Illinois, during the entire year, snow falls for 44.6 days and aggregates up to 16.46" (418mm) of snow.
What is the month with the least sunshine?
The month with the least sunshine in Harvey is January, with an average of 3.6h of sunshine.
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?
The month with the most rainfall is May, when the rain falls for 17.4 days and typically aggregates up to 4.17" (106mm) 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 6min 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 is the warmest month in Harvey?
Harvey witnesses the warmest weather in July, with temperatures averaging a high of 81.3°F (27.4°C) and a low of 65.8°F (18.8°C).
What month has the most sunshine?
With an average of 10.1h of sunshine, August has the most sunshine of the year in Harvey.
What is the least humid month?
October is the least humid month, with an average relative humidity of 73%.
What is the driest month?
December is the month with the least rainfall. Rain falls for 7.9 days and accumulates 1.54" (39mm) of precipitation.
What is the month with the shortest days?
December has the shortest days of the year, with an average of 9h and 12min of daylight.
What is the month with the lowest UV index?
With an average maximum UV index of 1, December is the month with the lowest UV index.
Average temperature
Harvey, IL
The warmest month (with the highest average high temperature) is July (81.3°F).
The month with the lowest average high temperature is January (29.7°F).
The month with the highest average low temperature is July (65.8°F).
The coldest month (with the lowest average low temperature) is January (18.9°F).
Average pressure
Harvey, IL
- Average pressure in January:
30.11"Hg - Average pressure in February:
30.1"Hg - Average pressure in March:
30.09"Hg - Average pressure in April:
29.95"Hg - Average pressure in May:
29.96"Hg - Average pressure in June:
29.92"Hg
- Average pressure in July:
29.97"Hg - Average pressure in August:
29.98"Hg - Average pressure in September:
30.03"Hg - Average pressure in October:
30.01"Hg - Average pressure in November:
30.1"Hg - Average pressure in December:
30.1"Hg
The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed
Harvey, IL
- Average wind speed in January:
10.2mph - Average wind speed in February:
9.9mph - Average wind speed in March:
9.5mph - Average wind speed in April:
9.8mph - Average wind speed in May:
8.3mph - Average wind speed in June:
7.4mph
- Average wind speed in July:
6.4mph - Average wind speed in August:
6.3mph - Average wind speed in September:
7.3mph - Average wind speed in October:
9.1mph - Average wind speed in November:
9.8mph - Average wind speed in December:
9.5mph
The windiest month (with the highest average wind speed) is January (10.2mph).
The calmest month (with the lowest average wind speed) is August (6.3mph).
Average humidity
Harvey, IL
The months with the highest relative humidity are January and February (82%).
The month with the lowest relative humidity is October (73%).
Average rainfall
Harvey, IL
- Average rainfall in January:
1.77" - Average rainfall in February:
1.69" - Average rainfall in March:
2.09" - Average rainfall in April:
3.43" - Average rainfall in May:
4.17" - Average rainfall in June:
3.82"
- Average rainfall in July:
3.31" - Average rainfall in August:
2.56" - Average rainfall in September:
2.48" - Average rainfall in October:
2.76" - Average rainfall in November:
1.69" - Average rainfall in December:
1.54"
The wettest month (with the highest rainfall) is May (4.17").
The driest month (with the least rainfall) is December (1.54").
Average rainfall days
Harvey, IL
- Average rainfall days in January:
6.8 days - Average rainfall days in February:
6.1 days - Average rainfall days in March:
12.7 days - Average rainfall days in April:
16.8 days - Average rainfall days in May:
17.4 days - Average rainfall days in June:
17.4 days
- Average rainfall days in July:
17.6 days - Average rainfall days in August:
14.8 days - Average rainfall days in September:
13.4 days - Average rainfall days in October:
14.3 days - Average rainfall days in November:
10.4 days - Average rainfall days in December:
7.9 days
The month with the highest number of rainy days is July (17.6 days).
The month with the least rainy days is February (6.1 days).
Average snowfall
Harvey, IL
The month with the highest snowfall is January (4.53").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days
Harvey, IL
- Average snowfall days in January:
12.6 days - Average snowfall days in February:
10.5 days - Average snowfall days in March:
6.1 days - Average snowfall days in April:
1.9 days - Average snowfall days in May:
0.1 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:
0.3 days - Average snowfall days in November:
4 days - Average snowfall days in December:
9.1 days
The month with the highest number of snowfall days is January (12.6 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight / Average sunshine
Harvey, IL
- 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 3min - 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:
3h and 4min - Average sunshine in February:
3h and 5min - Average sunshine in March:
6h and 0min - Average sunshine in April:
7h and 4min - Average sunshine in May:
8h and 4min - Average sunshine in June:
9h and 4min
- Average sunshine in July:
9h and 5min - Average sunshine in August:
10h and 1min - Average sunshine in September:
8h and 5min - Average sunshine in October:
5h and 5min - Average sunshine in November:
5h and 1min - Average sunshine in December:
4h and 0min
The month with the most sunshine is August (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 3h and 36min).
Average sunshine days
Harvey, IL
- Average sunshine days in January:
13 days - Average sunshine days in February:
11.8 days - Average sunshine days in March:
13.8 days - Average sunshine days in April:
10.2 days - Average sunshine days in May:
11.8 days - Average sunshine days in June:
10.4 days
- Average sunshine days in July:
11.1 days - Average sunshine days in August:
13.3 days - Average sunshine days in September:
14 days - Average sunshine days in October:
14.4 days - Average sunshine days in November:
16.4 days - Average sunshine days in December:
15 days
The month with the most sunshine days is November (16.4 days).
The month with the least sunshine days is April (10.2 days).
Average UV index
Harvey, IL
The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover
Harvey, IL
The month with the most cloud cover is January (Cloud cover 62).
The month with the least cloud cover is August (Cloud cover 30).
Average visibility
Harvey, IL
The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).
Harvey, Illinois, USA
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