This is the short version of Philadelphia climate: monthly averages, with the monthly detail underneath. The gap between Jan and Jul is 25.6 C here: -1.0 C against 24.6 C. No month dominates: the wettest is Jun at 4.02 mm/day, the driest Jan at 2.50 mm/day. Taken together that is roughly 1,223 mm of rain a year for the grid cell. The build runs on a schedule and caches the last good response, so the numbers stay put even when the upstream API is having a bad day. Use the table for exact numbers, or the related pages below for neighbouring locations and periods.
Annual mean temperature 12.1 C
Warmest month Jul (24.6 C)
Coldest month Jan (-1.0 C)
Wettest month Jun (4.02 mm/day)
All-time record high 39.1 C
All-time record low -21.3 C
Annual precipitation 1,226 mm / year
Coordinates 39.95238, -75.16362
Population 1,573,916
Average monthly temperature and rainfall in Philadelphia
Month
Mean temp (C)
Rain (mm/day)
Record high (C)
Record low (C)
Jan
-1.0
2.50
20.1
-20.3
Feb
0.1
2.75
23.4
-20.4
Mar
4.5
3.21
24.3
-21.3
Apr
10.8
3.23
33.6
-5.0
May
16.5
3.10
31.6
0.2
Jun
21.6
4.02
34.8
6.8
Jul
24.6
3.99
38.9
10.7
Aug
24.0
3.89
39.1
11.1
Sep
20.4
3.40
36.5
5.0
Oct
13.5
3.54
34.8
-3.9
Nov
7.1
3.01
25.0
-8.2
Dec
2.0
3.58
22.4
-14.7
What the Philadelphia climate table shows
Values are multi-decadal climatological averages for the 39.95238, -75.16362 grid cell, not a single year. Rain is the daily mean, so a value of 2.00 mm/day is about 60 mm across a 30-day month. Averages smooth over extremes, so use them for planning rather than for what to pack for next Tuesday.
Frequently asked questions
Is Philadelphia climate data a forecast?
No. These are multi-decadal averages for the grid cell, not a prediction for any particular year.
Why do the numbers differ from a weather app?
An app shows one location on one day. These are long-run averages, so they smooth out single hot or cold spells.