Chester, Pennsylvania Weather
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Climate of Chester: monthly averages
Based on 25 years of satellite and reanalysis data (2001-2025), July is usually the hottest month in Chester, with average daytime highs around 30°C. January is the coolest, when nights typically fall to about -5°C and frost is possible on the coldest nights. That is a wide yearly range of roughly 36°C, so the seasons feel very different from each other.
The area receives about 1230 mm of rain in a typical year. Most of it falls from June to October and December (around 57% of the yearly total), and June is the wettest month at roughly 125 mm.
For outdoor plans and travel, May usually offers the most comfortable weather in Chester, with mild days and relatively little rain.
| Month | Avg high | Avg low | Rainfall | Humidity |
|---|---|---|---|---|
| Jan | 3° | -5° | 76 mm | 85% |
| Feb | 4° | -5° | 75 mm | 84% |
| Mar | 9° | -1° | 94 mm | 81% |
| Apr | 17° | 5° | 97 mm | 78% |
| May | 22° | 11° | 98 mm | 78% |
| Jun | 27° | 16° | 125 mm | 76% |
| Jul | 30° | 19° | 125 mm | 71% |
| Aug | 30° | 18° | 120 mm | 72% |
| Sep | 26° | 14° | 112 mm | 73% |
| Oct | 19° | 8° | 111 mm | 78% |
| Nov | 12° | 2° | 87 mm | 81% |
| Dec | 6° | -2° | 106 mm | 86% |
Source: NASA POWER (MERRA-2 reanalysis), averaged over the roughly 50 km grid area around Chester. Values describe typical conditions, not a forecast.
About Chester weather
Chester is a place in Pennsylvania's humid continental climate, from the Appalachians to the Delaware valley, located about 20 km south-west of Philadelphia. Chester gets warm, humid summers (June–August) each year. Chester closes out the year with cold winters (December–February) with regular snow. This page shows live, auto-refreshing weather for Chester: current conditions, an hourly breakdown, a 16-day outlook, a date-lookup tool for any past or future date, and real-time air quality, sourced from Open-Meteo. Local timezone: America/New_York.
Frequently asked questions
Chester is about 20 km south-west of Philadelphia, in Pennsylvania.
Chester sees cold winters (December–February) with regular snow.
The live current conditions, hourly forecast and 16-day outlook above are pulled in real time for Chester's exact coordinates. No fixed schedule, the page updates whenever you load it.
July is usually the hottest month in Chester, with average daytime highs of about 30°C and nights around 19°C.
The coldest nights come in January, when the average low is about -5°C and daytime highs reach around 3°C. Frost is possible on clear, calm nights.
Chester receives about 1230 mm of rain in a typical year. June is the wettest month at roughly 125 mm, and the main rainy period is June to October and December.
May usually offers the most comfortable weather in Chester, with mild daytime temperatures and little rain.
In November Chester typically sees daytime highs near 12°C and lows near 2°C, with about 87 mm of rain over the month and average humidity around 81%. Check the live forecast above for this week's actual conditions.
Up to 16 days ahead using the extended forecast and date picker above; further-out or historical dates use the same date lookup tool.
The current temperature for Chester updates automatically at the top of this page — scroll to the hourly strip below to see how it's expected to change over the day.
Chester's day-to-day weather follows the broader pattern of Pennsylvania described above. See the hourly weather forecast or the air quality index for more detail.