Belleville, Illinois Weather History

Illinois, United States  •  45 yrs data 📍 38.5139°N, 89.9868°W
°F / °C
☀️

Quick Climate Facts

(1981 – 2025)
Hottest Month
🔥
Aug
Avg 77°F
Min 56°F
Max 98°F
Coldest Month
❄️
Jan
Avg 30.8°F
Min 2.8°F
Max 58.8°F
Wettest Month
🌧️
May
122 mm
Driest Month
🏜️
Feb
61 mm
Most Humid
💧
Jan
83%
Least Humid
🌬️
Sep
68%
Highest Ever
🌡️
108.6°F
Jul 2012
Lowest Ever
🧊
-18.1°F
Jan 1982
Monthly Climate Data
Month 🌤️ High Low Avg Humid % Rain (mm) Wind (m/s) Solar (kWh/m²)

Showing average climate conditions across 45 years (1981–2025)

🌍 Weather in Belleville Across Seasons

❄️ Winter in Belleville

January is Belleville's coldest month, with average lows reaching 2.8°F.
🌡️ December to February (avg)  ·  6.3°F62.8°F

🧥 Pack heavy layers and prepare for snow — this is a Severe Winter destination.

☀️ Summer in Belleville

Summer temperatures in Belleville peak in August, climbing to 98.1°F.
🌡️ June to August (avg)  ·  55.4°F95.5°F

🌤️ Limit midday outdoor exposure and stay hydrated — this is an intense Hot Summer.

🌧️ Rainy Season in Belleville

Belleville sees its highest rainfall in May, receiving approximately 122 mm of precipitation.
🌧️ April to July (avg)  ·  up to 122 mm

☔ Moderate Rainfall expected — carry rain gear and plan outdoor activities around these months.

📅 Monthly Averages

🌡️ Temperature Patterns

Monthly averages · 1981–2025 climate normals · °F

🌡️ Belleville Monthly Temperature Guide

Aug is the hottest month in Belleville, with average highs reaching 98°F, while Jan is the coldest with lows dropping to 2.8°F.

Temperatures rise steadily from spring, peak in Aug, and gradually decline through fall into winter.

These seasonal patterns make summer ideal for outdoor activities, while winters bring freezing conditions and heavy snowfall.

🌧️ Rainfall Distribution

Monthly rainfall · 1981–2025 seasonal trends · mm/month

💨 Humidity & Wind Speed

Monthly averages · 1981–2025

💧 Rainfall & Humidity in Belleville

Belleville receives its highest rainfall in May, while humidity peaks during winter months.
🌧️ Wettest: May — 122 mm ☀️ Driest: Feb — 61 mm

💧 Humidity peaks at 83% in Jan · annual avg 76%

🌍 Climate Summary

Avg Annual Temp:55.6°F
Avg Annual Rainfall:1086 mm
Avg Humidity:76%
Data Period:1981 – 2025

Belleville Climate Overview

Belleville has a warm temperate climate with warm summers and freezing winters.

Temperatures peak in Aug and drop to their lowest in Jan, while rainfall is highest during spring and early summer months.

Humidity remains high throughout the year, especially during winter months, creating cold and damp conditions.

📈 Yearly Trends

The warmest year in Belleville's recorded history was 2012 (avg: 60.3°F), while the coldest year was 1985 (avg: 51.3°F), based on annual average temperatures.

📊 Key Climate Trends

🌡️ Annual Temperature Trend

View Range:

Average annual high/low · Last 10 years · °F

Belleville's temperatures shows a slight warming trend over the past decade. The highest recorded temperature reached 108.6°F in Jul 2012, while the lowest dropped to -18.1°F in Jan 1982.

🌧️ Annual Precipitation

View Range:

Total annual precipitation · Last 10 years · mm/year

Annual rainfall in Belleville shows noticeable variation. Rainfall has decreased in recent years compared to earlier periods.
📋 Yearly Climate Data Overview

🔥 hottest  ·  ❄️ coldest  ·  🌧️ wettest

Year Min Temp Avg Temp Max Temp Rainfall (mm) Avg Humidity Avg Wind

🏙️ Other Cities in Illinois

Looking for another state? 🇺🇸 Explore All US States & Cities →

❓ Frequently Asked Questions

What is the hottest month in Belleville?
Based on 45 years of data (1981–2025), Aug is typically the hottest month in Belleville, Illinois, with average high temperatures around 98°F.
What is the coldest month in Belleville?
Jan is the coldest month in Belleville, with average low temperatures around 2.8°F.
What is the rainiest month in Belleville?
May receives the most rainfall with approximately 122 mm, while Feb is the driest with 61 mm.
What was the highest temperature ever recorded in Belleville?
The highest recorded temperature was 108.6°F in Jul 2012. This is part of the historical record spanning 1981–2025.
What was the lowest temperature ever recorded in Belleville?
The lowest recorded temperature was -18.1°F in Jan 1982.
How many years of data does this page cover?
This page covers 45 years of climate data from 1981 to 2025. As new data is added to the database the page automatically reflects the updated coverage.
How much sunlight does Belleville get?
Belleville receives the most sunlight in Jun with an average solar radiation of 6.29 kWh/m²/day. This solar radiation data, sourced from NASA POWER, is useful for solar energy planning, agriculture, and understanding seasonal sunshine availability in Illinois.
Where does this weather data come from?
All climate data is sourced from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite and model data. It provides monthly averages for temperature, precipitation, humidity, wind speed, and solar radiation.

📚 Data Source

All weather data is sourced from NASA POWER (Prediction of Worldwide Energy Resources), a NASA project providing solar and meteorological data for renewable energy, building efficiency, and agricultural research.

Parameters included:
  • Temperature (Min, Max)
  • Precipitation
  • Relative Humidity
  • Wind Speed
  • Solar Radiation
Data specifications:
  • Resolution: Monthly
  • Spatial: 0.5° × 0.625°
  • Source: MERRA-2
  • Coverage: 1981–2025
  • Years: 45