Climateby Month

San Bernardino, CA climate by month

NOAA 1991-2020 normals · 1,051 ft elevation · also covers Moreno Valley, Rialto

Summers in San Bernardino are hot; winters are mild. Highs peak at 96°F in August and fall to 67°F in December. The wettest month is February (about 8 wet days) and the driest is August (about 1). Snow is rare. The most comfortable time to visit is March, April and May.

Warmest month
96°F
August normal high
Coldest month
40°F
December normal low
Wet days a year
43
12.9 in of precipitation
Muggy days a year
2
dew point 65°F or higher

How warm is San Bernardino?

Normal highs range from 67°F in December to 96°F in August.

40°60°80°100° January: normal high 67°F (19°C), low 41°F (5°C) 67° 41° February: normal high 67°F (19°C), low 42°F (6°C) March: normal high 71°F (22°C), low 45°F (7°C) April: normal high 76°F (24°C), low 48°F (9°C) May: normal high 80°F (27°C), low 52°F (11°C) June: normal high 89°F (32°C), low 56°F (13°C) July: normal high 95°F (35°C), low 63°F (17°C) August: normal high 96°F (36°C), low 63°F (17°C) 96° 63° September: normal high 92°F (33°C), low 60°F (16°C) October: normal high 83°F (28°C), low 53°F (12°C) November: normal high 75°F (24°C), low 45°F (7°C) December: normal high 67°F (19°C), low 40°F (4°C) JFMAMJJASOND

Bars run from the normal low to the normal high for each month.

How rainy is San Bernardino?

February has the most wet days (about 8); the year brings about 13 in of precipitation.

January: 7 wet days February: 8 wet days 8 March: 6 wet days April: 4 wet days May: 3 wet days June: 1 wet days July: 1 wet days August: 1 wet days 1 September: 1 wet days October: 3 wet days November: 4 wet days December: 6 wet days JFMAMJJASOND

Wet day: at least 0.01 in of rain or melted snow, counted from daily records 1991-2020.

How humid is San Bernardino?

Muggy days peak in July, at about 1 days.

January: 0 muggy days 0 February: 0 muggy days March: 0 muggy days April: 0 muggy days May: 0 muggy days June: 0 muggy days July: 1 muggy days 1 August: 0 muggy days September: 1 muggy days October: 0 muggy days November: 0 muggy days December: 0 muggy days JFMAMJJASOND

Muggy day: daily mean dew point of 65°F or higher, from hourly observations 1991-2020 at March Air Reserve Base, 15 mi S of the city center.

How much daylight?

Daylight ranges from about 9.9 hours in December to 14.4 hours in June.

January: 10.2 hours of daylight February: 11.0 hours of daylight March: 12.0 hours of daylight April: 13.1 hours of daylight May: 13.9 hours of daylight June: 14.4 hours of daylight 14.4 July: 14.2 hours of daylight August: 13.4 hours of daylight September: 12.4 hours of daylight October: 11.3 hours of daylight November: 10.4 hours of daylight December: 9.9 hours of daylight 9.9 JFMAMJJASOND
See all numbers
Monthly climate normals and day counts for San Bernardino, 1991-2020
MonthHighLowPrecip.Wet daysMuggy daysDaylight
January 67°F41°F 2.8 in7 0 10.2 h
February 67°F42°F 3.0 in8 0 11.0 h
March 71°F45°F 2.0 in6 0 12.0 h
April 76°F48°F 0.9 in4 0 13.1 h
May 80°F52°F 0.3 in3 0 13.9 h
June 89°F56°F 0.1 in1 0 14.4 h
July 95°F63°F 0.1 in1 1 14.2 h
August 96°F63°F 0.09 in1 0 13.4 h
September 92°F60°F 0.1 in1 1 12.4 h
October 83°F53°F 0.5 in3 0 11.3 h
November 75°F45°F 0.9 in4 0 10.4 h
December 67°F40°F 2.0 in6 0 9.9 h

High and low: NOAA 1991-2020 normal daily high and low. Wet days: at least 0.01 in of rain or melted snow. Muggy days: daily mean dew point 65°F or higher.

Best months to visit San Bernardino

By our comfort score, the best months are March, April and May.

Comfort score by month (0-100) and its parts, in days per month
MonthScoreComfortableNotable rainHot or cold
Jan 661750
Feb 641350
Mar 711741
Apr 721523
May 701416
Jun 565014
Jul 420124
Aug 390026
Sep 444021
Oct 591219
Nov 681621
Dec 641540

Score = 40 × share of comfortable days + 25 × share of days without notable rain + 20 × share of days neither hot (90°F+) nor cold (high 40°F or below) + 15 × daylight. How the score works.

Frost dates in San Bernardino

The last spring frost typically comes around Jan 27, and the first fall frost around Dec 19, leaving 329 frost-free days in a typical year.

Frost and freeze dates for San Bernardino
Typical date1 year in 10
Last spring frost (32°F)Jan 27after Feb 28
First fall frost (32°F)Dec 19before Dec 1
Hard freeze (28°F)in about 26% of years; no typical date
Frost-free season329 daysunder 292 days

"Typical" is the date with a 50% chance of a later spring frost (or earlier fall frost). Planting after the "1 year in 10" spring date gives a 90% chance of no further frost. The Old Farmer's Almanac publishes 30% dates, which fall between our typical and 1-in-10 dates.

Station: Redlands (USC00047306), NOAA 1991-2020 freeze probabilities. Frost dates for every city in California.

Hottest and coldest readings, 1991-2020

The highest reading was 118°F (July 22, 2006); the lowest was 24°F (January 14, 2007).

From the temperature station's daily records with NOAA quality flags removed. Not an all-time record.

Near San Bernardino

Similar climates elsewhere

Also covers

Moreno Valley and Rialto use the same temperature and rain stations as San Bernardino, so their monthly numbers are the ones on this page.

Where the numbers come from

  • Temperature, rain, snowfall, snow depth and frost dates: Redlands (USC00047306), 7.3 mi SE of the city center, 1,410 ft (359 ft higher than the city). NOAA normals and daily records, 1991-2020.
  • Humidity and wind by hour and cloud cover: March AFB (USW00023119), 15 mi S of the city center, 1,516 ft (465 ft higher than the city). NOAA normals and daily records, 1991-2020.
  • Daily humidity and wind: March Air Reserve Base (722860-23119), 15 mi S of the city center, 1,536 ft (485 ft higher than the city). Hourly observations, 1991-2020.

Distances from the city center (USGS). Methodology · Report an error