Climate and monthly weather forecastPetersburg, IL
Climate and monthly weather forecast
Weather in January
January, the same as December, is another cold winter month in Petersburg, Illinois, with an average temperature fluctuating between 32.9°F (0.5°C) and 20.7°F (-6.3°C). The month of January sees the lowest average temperatures, reaching 32.9°F (0.5°C) at the peak and 20.7°F (-6.3°C) at the low. Weather in January »Weather in February
The last month of the winter, February, is another cold month in Petersburg, Illinois, with an average temperature ranging between min 24.4°F (-4.2°C) and max 37.9°F (3.3°C). Petersburg marks the arrival of February with an average high-temperature of a still wintry 37.9°F (3.3°C), hardly different from January's 32.9°F (0.5°C). Weather in February »Weather in March
March, the first month of the spring in Petersburg, is a cool month, with an average temperature ranging between min 35.2°F (1.8°C) and max 50.9°F (10.5°C). With the onset of March, the average high-temperature slightly shifts from February's cold 37.9°F (3.3°C) to a cool 50.9°F (10.5°C). Weather in March »Weather in April
April in Petersburg, Illinois, is an enjoyable spring month, with temperature in the range of an average low of 46°F (7.8°C) and an average high of 63°F (17.2°C). As Petersburg transitions into April, a rise in the average high-temperature is observed, moving from a fresh 50.9°F (10.5°C) in March to a refreshing 63°F (17.2°C). Weather in April »Weather in May
May, the last month of the spring in Petersburg, is an agreeable month, with an average temperature varying between 55.9°F (13.3°C) and 72.9°F (22.7°C). Petersburg in May experiences an increase in the average high-temperature, moving from April's enjoyable 63°F (17.2°C) to a pleasant 72.9°F (22.7°C). Weather in May »Weather in June
June, the first month of the summer in Petersburg, is a warm month, with an average temperature fluctuating between 64.2°F (17.9°C) and 81°F (27.2°C). As June arrives, a slight rise in the average high-temperature is observed, moving from an agreeable 72.9°F (22.7°C) in May to a moderately hot 81°F (27.2°C). Weather in June »Weather in July
July, like June, in Petersburg, Illinois, is a moderately hot summer month, with an average temperature fluctuating between 66°F (18.9°C) and 82.8°F (28.2°C). Petersburg's temperatures peak on average in July, reaching 82.8°F (28.2°C) at their highest and 66°F (18.9°C) at their lowest. The heat index in July is computed to be a hot 91.4°F (33°C). Weather in July »Weather in August
The last month of the summer, August, is another warm month in Petersburg, Illinois, with an average temperature ranging between max 82°F (27.8°C) and min 64°F (17.8°C). Petersburg observes a minor difference in average high-temperatures between July's 82.8°F (28.2°C) and August's 82°F (27.8°C). Weather in August »Weather in September
September, the first month of the autumn in Petersburg, is still a warm month, with an average temperature fluctuating between 77.4°F (25.2°C) and 58.5°F (14.7°C). The arrival of September sees a recorded average high-temperature of a still moderately hot 77.4°F (25.2°C), showing little divergence from the previous month's conditions. Weather in September »Weather in October
October, like September, in Petersburg, Illinois, is another refreshing autumn month, with an average temperature ranging between max 63.9°F (17.7°C) and min 47.7°F (8.7°C). The transition into October involves a decrease in the average high-temperature, falling from a moderately hot 77.4°F (25.2°C) in September to a refreshing 63.9°F (17.7°C). Weather in October »Weather in November
The last month of the autumn, November, is also a fresh month in Petersburg, Illinois, with an average temperature fluctuating between 50°F (10°C) and 36°F (2.2°C). November suggests a modest reduction in the average high-temperature, shifting from an enjoyable 63.9°F (17.7°C) in October to a fresh 50°F (10°C). Weather in November »Weather in December
The first month of the winter, December, is also an icy month in Petersburg, Illinois, with an average temperature ranging between max 38.5°F (3.6°C) and min 27.5°F (-2.5°C). With December's arrival, Petersburg, Illinois, sees a decrease in average high-temperatures, moving from a fresh 50°F (10°C) in November to a wintry 38.5°F (3.6°C). Weather in December »Updated: Feb 12, 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
January, known for its average high temperature of 32.9°F (0.5°C) and an average low temperature of 20.7°F (-6.3°C), is the coldest month.
Throughout the year, in Petersburg, Illinois, there are 146.4 rainfall days, and 30.67" (779mm) of precipitation is accumulated.
January through April, October through December are months with snowfall.
January is the month with the most snowfall in Petersburg. Snow falls for 10.3 days and accumulates 4.02" (102mm) of snow.
In Petersburg, during the entire year, snow falls for 29.2 days and aggregates up to 10.39" (264mm) of snow.
January has the least sunshine of the year, with an average of 4.1h of sunshine.
The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2.
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.
The month with the most rainfall is May, when the rain falls for 18.3 days and typically aggregates up to 3.82" (97mm) of precipitation.
In Petersburg, Illinois, snow does not fall in May through September.
The month with the longest days in Petersburg is June, with an average of 15h and 0min of daylight.
June has the most sunshine of the year, with an average of 10.2h of sunshine.
June through August, with an average maximum UV index of 6, are months with the highest UV index in Petersburg.
With average high temperatures of 82.8°F (28.2°C) and lows of 66°F (18.9°C), July is the warmest month.
The most humid month in Petersburg, Illinois, is July, with an average relative humidity of 84%.
With an average relative humidity of 70%, October is the least humid month in Petersburg.
December is the month with the least rainfall in Petersburg, Illinois. Rain falls for 8.1 days and accumulates 1.5" (38mm) of precipitation.
The month with the shortest days in Petersburg, Illinois, is December, with an average of 9h and 24min of daylight.
Average temperature
Petersburg, IL
The warmest month (with the highest average high temperature) is July (82.8°F).
The month with the lowest average high temperature is January (32.9°F).
The month with the highest average low temperature is July (66°F).
The coldest month (with the lowest average low temperature) is January (20.7°F).
Average pressure
Petersburg, IL
- Average pressure in January:
30.15"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:
29.95"Hg - Average pressure in June:
29.91"Hg
- Average pressure in July:
29.97"Hg - Average pressure in August:
29.97"Hg - Average pressure in September:
30.02"Hg - Average pressure in October:
30.02"Hg - Average pressure in November:
30.11"Hg - Average pressure in December:
30.12"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed
Petersburg, IL
- Average wind speed in January:
10.3mph - Average wind speed in February:
10.3mph - Average wind speed in March:
10.1mph - Average wind speed in April:
10.3mph - Average wind speed in May:
8.6mph - Average wind speed in June:
7.5mph
- Average wind speed in July:
6.3mph - Average wind speed in August:
6.3mph - Average wind speed in September:
7.2mph - Average wind speed in October:
9.1mph - Average wind speed in November:
9.9mph - Average wind speed in December:
9.7mph
The windiest months (with the highest average wind speed) are January, February and April (10.3mph).
The calmest months (with the lowest average wind speed) are July and August (6.3mph).
Average humidity
Petersburg, IL
The month with the highest relative humidity is July (84%).
The month with the lowest relative humidity is October (70%).
Average rainfall
Petersburg, IL
- Average rainfall in January:
1.77" - Average rainfall in February:
1.73" - Average rainfall in March:
2.44" - Average rainfall in April:
3.54" - Average rainfall in May:
3.82" - Average rainfall in June:
3.5"
The wettest month (with the highest rainfall) is May (3.82").
The driest month (with the least rainfall) is December (1.5").
Average rainfall days
Petersburg, IL
- Average rainfall days in January:
7.1 days - Average rainfall days in February:
6.2 days - Average rainfall days in March:
12.9 days - Average rainfall days in April:
15.5 days - Average rainfall days in May:
18.3 days - Average rainfall days in June:
16.3 days
- Average rainfall days in July:
15.9 days - Average rainfall days in August:
13.2 days - Average rainfall days in September:
11.9 days - Average rainfall days in October:
11.6 days - Average rainfall days in November:
9.4 days - Average rainfall days in December:
8.1 days
The month with the highest number of rainy days is May (18.3 days).
The month with the least rainy days is February (6.2 days).
Average snowfall
Petersburg, IL
The month with the highest snowfall is January (4.02").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days
Petersburg, IL
- Average snowfall days in January:
10.3 days - Average snowfall days in February:
7.6 days - Average snowfall days in March:
3.5 days - Average snowfall days in April:
0.8 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:
0.2 days - Average snowfall days in November:
2 days - Average snowfall days in December:
4.8 days
The month with the highest number of snowfall days is January (10.3 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight / Average sunshine
Petersburg, IL
- Average daylight in January:
9h and 42min - Average daylight in February:
10h and 42min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 18min - Average daylight in May:
14h and 24min - Average daylight in June:
15h and 0min
- Average daylight in July:
14h and 42min - Average daylight in August:
13h and 42min - Average daylight in September:
12h and 24min - Average daylight in October:
11h and 6min - Average daylight in November:
10h and 0min - Average daylight in December:
9h and 24min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in January:
4h and 6min - Average sunshine in February:
4h and 24min - Average sunshine in March:
6h and 24min - Average sunshine in April:
8h and 0min - Average sunshine in May:
9h and 6min - Average sunshine in June:
10h and 12min
- Average sunshine in July:
10h and 0min - Average sunshine in August:
9h and 42min - Average sunshine in September:
9h and 6min - Average sunshine in October:
5h and 48min - Average sunshine in November:
5h and 12min - Average sunshine in December:
4h and 30min
The month with the most sunshine is June (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).
Average sunshine days
Petersburg, IL
- Average sunshine days in January:
15.2 days - Average sunshine days in February:
15.3 days - Average sunshine days in March:
15.1 days - Average sunshine days in April:
11.7 days - Average sunshine days in May:
11.3 days - Average sunshine days in June:
11.9 days
- Average sunshine days in July:
12.2 days - Average sunshine days in August:
16.3 days - Average sunshine days in September:
16.1 days - Average sunshine days in October:
17.6 days - Average sunshine days in November:
18.5 days - Average sunshine days in December:
18.1 days
The month with the most sunshine days is November (18.5 days).
The month with the least sunshine days is May (11.3 days).
Average UV index
Petersburg, IL
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, November and December (UV index 2).
Average cloud cover
Petersburg, IL
The month with the most cloud cover is January (Cloud cover 56).
The month with the least cloud cover is August (Cloud cover 30).
Average visibility
Petersburg, IL
The months with the highest visibility are January, February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are July and August (5mi).
