Marion climate — normals and trends
Marion (United States) has a humid subtropical climate (Cfa) under the Köppen-Geiger classification. Its mean annual temperature is 14.2 °C and it receives 1,065 mm of precipitation per year.
These figures are normals computed over 86 complete calendar years, from 1940 to 2025, using ERA5 reanalysis data from the Copernicus programme.
The warmest month is July (26.3 °C on average) and the coldest is January (0.7 °C). Rainfall peaks in April.
Marion averages 72 frost days, 64 hot days (≥ 30 °C) and 112 rainy days per year.
Marion has warmed by +1.3 °C between 1940 and 2025, or +0.15 °C per decade. This trend is statistically significant.
The number of frost days there went from about 82 to 62 per year over the period.
The hottest day of the period reached 41.2 °C (on 28 June 2012) and the coldest -28.1 °C (on 2 February 1951).
Data from ERA5 reanalysis (Copernicus Climate Change Service), redistributed under a CC-BY 4.0 licence. Normals are recomputed whenever the archive is updated.
Climate normals · ERA5
MarionIllinois
- coords
- 37.73°, -88.93°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
14.2°C
Average daily high
19.1°C
Average daily low
9.6°C
Annual rainfall
1,065mm
Sunshine / day
9.1h
Mean relative humidity
68%
Average peak wind
16.4km/h
Seasonal range
25.6°C
Frost days (< 0 °C)
72 d/yr
Hot days (≥ 30 °C)
64 d/yr
Rainy days (≥ 1 mm)
112 d/yr
Annual snowfall
30.6 cm
Average feels-like high
18.2 °C
Average feels-like low
7.8 °C
Average peak gust
36.3 km/h
Tropical nights (≥ 20 °C)
72 d/yr
Solar radiation
15.7 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.3 °C
since 1940
+0.2 °C per decade · r² = 0.24 · p = < 0.001
Trend fitted by linear regression (ordinary least squares) on annual means. A trend is shown only when it is statistically significant (p < 0.05).
A climograph overlays rainfall (bars) and temperature (line): the standard reading in climatology, where you can see at a glance whether the warm season is also the dry one.
Records for the period
Hottest day
41.2 °C
28 June 2012
Coldest day
-28.1 °C
2 February 1951
Wettest day
148 mm
14 August 2023
Windiest day
48.1 km/h
5 April 1947
Strongest gust
113.0 km/h
30 March 2022
Hottest feels-like
44.9 °C
2 July 1980
Coldest feels-like
-33.5 °C
2 February 1951
Snowiest day
23.8 cm
6 April 1971
Sunniest day
14.0 h
20 May 1940
Normals computed over complete calendar years 1940–2025.
A specific year
Pick a year and see how it compares to normal — warmer, drier or more extreme than usual?
Across the whole year
Month by month
| High | vs. normal | Precipitation | vs. normal | |
|---|---|---|---|---|
| Jan | 3.4 °C | -1.5 °C | 92 mm | +12 mm |
| Feb | 7.6 °C | 0.0 °C | 110 mm | +31 mm |
| Mar | 18.2 °C | +4.9 °C | 72 mm | -39 mm |
| Apr | 21.4 °C | +1.8 °C | 208 mm | +93 mm |
| May | 23.2 °C | -1.3 °C | 170 mm | +59 mm |
| Jun | 29.6 °C | +0.2 °C | 153 mm | +66 mm |
| Jul | 31.6 °C | +0.4 °C | 100 mm | +16 mm |
| Aug | 30.2 °C | -0.2 °C | 7 mm | -69 mm |
| Sep | 29.2 °C | +2.3 °C | 51 mm | -19 mm |
| Oct | 22.4 °C | +1.6 °C | 107 mm | +28 mm |
| Nov | 14.9 °C | +1.9 °C | 72 mm | -18 mm |
| Dec | 7.9 °C | +0.8 °C | 31 mm | -51 mm |
The year's extremes
What was the weather like that day?
Your birthday, a wedding, a memorable trip: discover the actual weather for any date since 1940.
Frequently asked questions
What is the climate of Marion?
Marion has a humid subtropical climate (Köppen Cfa). Over 1940-2025, the average annual temperature is 14.2 °C and it receives 1,065 mm of precipitation per year.
What is the hottest day ever recorded in Marion?
The hottest day measured in Marion between 1940 and 2025 was 28 June 2012, reaching 41.2 °C.
What is the coldest day in Marion?
The coldest day measured in Marion between 1940 and 2025 was 2 February 1951, at -28.1 °C.
Does it snow in Marion?
Yes. Marion gets on average 30.6 cm of snow per year and has around 72 frost days.
Has the climate of Marion warmed?
Yes: Marion warmed by +1.3 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Marion?
The wettest day measured in Marion between 1940 and 2025 was 14 August 2023, with 148 mm of rain in 24 hours.
What was the windiest day in Marion?
The windiest day measured in Marion between 1940 and 2025 was 5 April 1947, with winds reaching 48.1 km/h.
What is the warmest month in Marion?
The warmest month in Marion is July (26.3 °C on average); the coldest is January (0.7 °C).
How much does it rain in Marion?
Marion receives on average 1,065 mm of precipitation per year, spread over about 112 rainy days.
Is it sunny in Marion?
Marion gets on average 9.1 hours of sunshine per day, roughly 3,322 hours per year over 1940-2025.
What is the biggest single-day snowfall in Marion?
The heaviest 24-hour snowfall measured in Marion between 1940 and 2025 was 6 April 1971, with 23.8 cm.
Are there tropical nights in Marion?
Yes: Marion has on average 72 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Marion?
In Marion, between 1940 and 2025, the highest apparent temperature reached 44.9 °C on 2 July 1980, and the lowest was -33.5 °C on 2 February 1951.
Compare Marion with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Marion