Mattoon, United States experiences average highs of 18°C (64°F) and lows of 9°C (48°F) throughout the year. Rainfall is moderate, averaging about 10 rainy days per month. Sunshine is abundant, averaging about 9 hours per day. Average highs have stayed broadly stable across the available records.
Mattoon, United States Weather & Climate 2026
Monthly climate averages for Mattoon, United States. Based on 10-year ERA5 reanalysis data.
Climate Overview
Drier season: Jan–Dec 
Wetter season: Mar–Jul At-a-Glance Climate Summary
Live Weather & Air Quality
Key figures
Climate Score
5.5/10
Best: May, June, August, September, October
UV Index
5
Low
Temperature 18°C / 9°C
Feels Like 17°C / 7°C
Rainy Days 10
Rainfall 93 mm
Sunshine 9 h
Humidity 69%
Wind Speed 20 km/h
Dew Point 8°C
Snow Days 4 days
Frost Days 14 days
Hottest Month
29°C
July
Avg Low21°C
Rain12days
Coldest Month
-4°C
January
Avg High3°C
Rain9days
Driest Month
7days
September
Avg High27°C
Avg Low17°C
Windiest Month
23 km/h
April (Gusts 47)
Worst Time to Visit
Consider avoiding January, February, December due to very cold temperatures.
Sun Position
Sunrise 05:27
Daylight 14.9h
Sunset 20:24
Live conditions—
Mattoon on the map · live conditions
Mattoon, United States
- Continent
- Americas
- Country
- United States
- City
- Mattoon
- Population
- 18.1K
- Elevation
- 224 m
- Coordinates
- 39.48°, -88.37°
Seasonal Breakdown
Spring
Mar–May
Avg High 18°C
Avg Low 8°C
Rain 12 days/mo
1/3 best months
Summer
Jun–Aug
Avg High 29°C
Avg Low 20°C
Rain 10 days/mo
2/3 best months
Autumn
Sep–Nov
Avg High 19°C
Avg Low 10°C
Rain 8 days/mo
2/3 best months
Winter
Dec–Feb
Avg High 6°C
Avg Low -3°C
Rain 9 days/mo
Climate Charts
Based on historical averages (2016–2025)
Monthly Temperatures
HighLowShaded bands show the typical range across the available yearly records.
Line chart showing monthly temperatures. Jan: 3°C / -4°C . Feb: 7°C / -3°C . Mar: 13°C / 3°C . Apr: 18°C / 7°C . May: 23°C / 14°C . Jun: 29°C / 19°C . Jul: 29°C / 21°C . Aug: 28°C / 20°C . Sep: 27°C / 17°C . Oct: 20°C / 11°C . Nov: 12°C / 3°C . Dec: 6°C / -1°C .
Monthly Rainfall
Rainfall
Bar chart showing monthly rainfall. Jan: 74 mm. Feb: 69 mm. Mar: 112 mm. Apr: 127 mm. May: 109 mm. Jun: 97 mm. Jul: 137 mm. Aug: 95 mm. Sep: 68 mm. Oct: 88 mm. Nov: 73 mm. Dec: 67 mm.
Monthly Humidity
Humidity
Line chart showing monthly humidity. Jan: 70%. Feb: 68%. Mar: 66%. Apr: 65%. May: 69%. Jun: 66%. Jul: 74%. Aug: 73%. Sep: 67%. Oct: 66%. Nov: 69%. Dec: 72%.
Monthly Wind Speed
Wind SpeedGusts
Bar chart showing monthly wind speed. Jan: 21 km/h . Feb: 22 km/h . Mar: 23 km/h . Apr: 23 km/h . May: 20 km/h . Jun: 18 km/h . Jul: 15 km/h . Aug: 15 km/h . Sep: 16 km/h . Oct: 20 km/h . Nov: 21 km/h . Dec: 21 km/h .
Sunshine
Sunshine
Sunshine: Jan: 5h. Feb: 7h. Mar: 8h. Apr: 9h. May: 10h. Jun: 12h. Jul: 12h. Aug: 11h. Sep: 10h. Oct: 8h. Nov: 7h. Dec: 5h.
UV Index
UV Index
Bar chart showing monthly UV index. Jan: UV 3. Feb: UV 4. Mar: UV 5. Apr: UV 6. May: UV 7. Jun: UV 7. Jul: UV 7. Aug: UV 7. Sep: UV 6. Oct: UV 4. Nov: UV 3. Dec: UV 2.
Monthly Daylight Hours
Daylight12h reference
Monthly Dew Point & Comfort
Dew Point Dry Comfortable Humid Muggy Oppressive
Snow Days
Snow DaysSnowfall
Snow Days: Jan: 7 days. Feb: 6 days. Mar: 2 days. Apr: 1 days. May: 0 days. Jun: 0 days. Jul: 0 days. Aug: 0 days. Sep: 0 days. Oct: 0 days. Nov: 2 days. Dec: 4 days.
Climate Trends
Average highs have stayed broadly stable across the available records. Average rainfall is trending drier by about 9 mm.
2016 to 2025
Avg high Avg rainfall
Climate summary
| Last 12 months | All years | |
|---|---|---|
| Hottest month | Jul 2025 · 30°C | Jul · 29°C |
| Coldest month | Jan 2025 · -8°C | Jan · -4°C |
| Wettest month | Jun 2025 · 161 mm | Jul · 137 mm |
| Windiest month | Mar 2025 · 25 km/h | Apr · 23 km/h |
Month-by-Month Weather Table
January
Poor 
February
Poor March
Poor April
Fair May best
Excellent June best
Excellent July
Good August best
Excellent September best
Excellent October best
Good November
Poor December
Poor | Month | Temp | Feels Like | Rain | Sun | Humidity | UV | Status | Details |
|---|---|---|---|---|---|---|---|---|
| January | 3°C / -4°C | -1°C / -9°C | 9days (74 mm) Wet | 5.3h Fair | 70% Muggy | 2.5 Moderate | Poor | View Details |
| February | 7°C / -3°C | 3°C / -8°C | 8days (69 mm) Wet | 6.7h Fair | 68% Muggy | 3.7 Moderate | Poor | View Details |
| March | 13°C / 3°C | 10°C / -2°C | 12days (112 mm) Wet | 7.5h Good | 66% Muggy | 4.8 Moderate | Poor | View Details |
| April | 18°C / 7°C | 16°C / 4°C | 12days (127 mm) Wet | 8.9h Good | 65% Muggy | 5.7 High | Fair | View Details |
| May best | 23°C / 14°C | 23°C / 12°C | 13days (109 mm) Wet | 10h Excellent | 69% Muggy | 6.9 High | Excellent | View Details |
| June best | 29°C / 19°C | 30°C / 19°C | 10days (97 mm) Wet | 11.8h Excellent | 66% Muggy | 7.3 Very High | Excellent | View Details |
| July | 29°C / 21°C | 33°C / 23°C | 12days (137 mm) Wet | 11.9h Excellent | 74% Muggy | 7.3 Very High | Good | View Details |
| August best | 28°C / 20°C | 31°C / 21°C | 9days (95 mm) Wet | 11h Excellent | 73% Muggy | 6.8 High | Excellent | View Details |
| September best | 27°C / 17°C | 28°C / 17°C | 7days (68 mm) Good | 10h Excellent | 67% Muggy | 5.7 High | Excellent | View Details |
| October best | 20°C / 11°C | 18°C / 8°C | 9days (88 mm) Wet | 7.8h Good | 66% Muggy | 4.2 Moderate | Good | View Details |
| November | 12°C / 3°C | 8°C / -1°C | 8days (73 mm) Wet | 6.5h Fair | 69% Muggy | 2.9 Moderate | Poor | View Details |
| December | 6°C / -1°C | 3°C / -6°C | 9days (67 mm) Wet | 5.4h Fair | 72% Muggy | 2.2 Moderate | Poor | View Details |
Compare Nearby City Climates
Frequently Asked Questions
The best months to visit Mattoon are May, June, August, September, October, when temperatures are comfortable and rainfall is at its lowest. This is based on 10-year climate averages for Mattoon, scoring temperature, rainfall, humidity, and sunshine hours.
The hottest month in Mattoon is July, with average daytime highs of 29°C (85°F). Plan outdoor activities for early morning or late afternoon if visiting during this period.
The coldest month in Mattoon is January, with average overnight lows of -4°C (24°F). Pack warm layers and expect shorter daylight hours during this period.
The wettest month in Mattoon is July, averaging 137mm of precipitation across 12 rainy days. An umbrella or waterproof jacket is essential.
The rainy season in Mattoon runs through May, March, April, July, with the heaviest rainfall in May. Based on 10-year averages for Mattoon.
Mattoon receives approximately 103 sunshine hours per year. The sunniest month is July with around 12 hours. Based on climate data for Mattoon.
The least favorable months to visit Mattoon are January, February, December, primarily due to very cold temperatures. For the best conditions, consider May, June, August, September, October instead.
The annual average UV index in Mattoon is 5, classified as moderate. Standard sun protection (sunscreen, hat) is recommended during prolonged outdoor exposure.
Average humidity in Mattoon is 69%, classified as moderate. Humidity levels are generally comfortable and should not affect outdoor activities for most people.
Yes, Mattoon receives snow. Months with snowfall average 4 snow days and 6 cm (2 in) of accumulation, with about 14 frost days during winter.
Average wind speeds in Mattoon are 20 km/h (12 mph). The windiest month is April with peak winds reaching 23 km/h (14 mph) (gusts up to 47 km/h / 29 mph).
Mattoon averages 5 clear-sky days per month with overall cloud cover around 57%. The clearest skies occur in September.
The annual average dew point in Mattoon is 8°C (46°F), which feels dry and comfortable. Outdoor activities are comfortable year-round from a humidity standpoint.
Mattoon has a Humid Subtropical climate, classified as Cfa under the Köppen system. Temperate climates have mild winters and warm summers, with rainfall spread across the year and four distinct seasons.
The 'feels like' temperature in Mattoon ranges from 7°C (45°F) to 17°C (63°F) on average. The 'feels like' temperature closely matches the actual temperature throughout most of the year.
Yes, June is a great time to visit Mattoon. It earns a climate score of 8.7/10 with Excellent.
For June in Mattoon, pack Umbrella, Waterproof jacket, Breathable clothing, Sunscreen (SPF 30+), Sun hat. With average highs of 29°C (83°F) and 10 rainy days, these essentials will keep you comfortable.
Data Source
Climate data derived from ERA5 reanalysis (ECMWF), averaged over 2016–2025. Sea surface temperature from marine reanalysis data. Climate scores and seasonal estimates are computed by WorldStats.
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