San Antonio climate: monthly averages: annual mean temperature 20.6 C; warmest month Aug (29.6 C); coldest month Jan (10.1 C).
Annual mean temperature: 20.6 C
Warmest month: Aug (29.6 C)
Coldest month: Jan (10.1 C)
Wettest month: May (3.21 mm/day)
All-time record high: 44.5 C
All-time record low: -7.7 C
This is the short version of San Antonio climate: monthly averages, with the monthly detail underneath. The gap between Jan and Aug is 19.5 C here: 10.1 C against 29.6 C. No month dominates: the wettest is May at 3.21 mm/day, the driest Feb at 1.26 mm/day. Taken together that is roughly 776 mm of rain a year for the grid cell. Values come from a public open API; a successful result is cached so a later outage never blanks the page. Scroll for the month-by-month figures, or jump to a neighbouring location from the links below.
Annual mean temperature 20.6 C
Warmest month Aug (29.6 C)
Coldest month Jan (10.1 C)
Wettest month May (3.21 mm/day)
All-time record high 44.5 C
All-time record low -7.7 C
Annual precipitation 777 mm / year
Coordinates 29.42412, -98.49363
Population 1,526,656
Average monthly temperature and rainfall in San Antonio
Month
Mean temp (C)
Rain (mm/day)
Record high (C)
Record low (C)
Jan
10.1
1.58
29.0
-6.6
Feb
12.4
1.26
34.9
-7.7
Mar
16.8
1.98
35.1
-5.4
Apr
21.1
2.08
39.2
1.1
May
24.9
3.21
40.8
6.0
Jun
28.2
2.36
42.9
15.9
Jul
28.9
2.29
43.5
18.0
Aug
29.6
1.99
44.5
18.2
Sep
26.0
3.18
42.2
10.5
Oct
21.3
2.53
37.3
0.9
Nov
15.7
1.64
32.1
-3.8
Dec
11.1
1.44
28.9
-4.9
What the San Antonio climate table shows
Values are multi-decadal climatological averages for the 29.42412, -98.49363 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
Does San get the same every year?
Close to it. Averaging decades smooths variation, so treat these as typical rather than guaranteed.