Climate · San Antonio Heights

San Antonio Heights, CA climate

San Antonio Heights has warm winters and hot summers, with very little rain. A typical July afternoon reaches 92°, a January night drops to 46°, and snow is almost unheard of.

NOAA 1991-2020 climate normals Updated once a decade
July high
92°
676th hottest of 1,618 California towns
January low
46°
165th mildest of 1,618 California towns
Rain + melted snow
20 in
665th wettest of 1,618 California towns
Snow a winter
0.0 in
470th snowiest of 1,499 California towns
A normal year

What a year in San Antonio Heights feels like

Winter

65° / 45°
Typical high / low · Snow is rare

Spring

73° / 49°
Typical high / low · Frost is rare by spring

Summer

90° / 62°
Typical high / low · 93 days reach 90° in a normal year

Fall

81° / 57°
Typical high / low · Mild well into the fall
Best months to be outsideJanFebMarAprMayOctNovDecHighs of 62–84° and lows of 40° or more
Month by month

San Antonio Heights weather by month

Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.

MonthHighLowRain + meltSnowWet daysSnow on ground30-yr range
January65°46°4.5" 070 52° – 62°
February66°46°5.1" 070 48° – 65°
March69°46°3.3" 060 51° – 65°
April73°49°1.1" 040 55° – 65°
May78°53°0.6" 030 59° – 73°
June85°58°0.1" 020 66° – 77°
July92°64°0.1" 010 72° – 83°
August94°65°0.0" 000 76° – 83°
September90°64°0.1" 010 72° – 81°
October81°57°0.9" 030 64° – 74°
November72°50°1.3" 030 53° – 66°
December65°44°3.3" 060 50° – 61°
Year77°53°20.4"0.0"420

“Wet days” have at least 0.01" of rain or melted snow. “Snow on ground” counts days with 1" or more. The 30-year range is the coldest and warmest that month’s average temperature got between 1991 and 2020.

Rain & snow

Rain and snow in San Antonio Heights

San Antonio Heights gets 20 inches of rain and melted snow a year. February is the wettest month and August the driest. Rain or snow falls on about 42 days a year.

20 in
Rain + melted snow a year
Less rain than 88% of U.S. towns
0.0 in
Snow in a normal winter
Less snow than 96% of U.S. towns
0 days
With 1"+ of snow on the ground
Fewer than 94% of U.S. towns

Rain + melted snow by month

Inches of water
5.1"

Snowfall by month

No measurable snow in a normal year.
Frost & the growing season

A year-round growing season

🌿 Only about half of winters dip to 32° here (41% of years), so gardens can grow year-round.
2
nights at or below 32° in a normal year
0
nights below 0° in a normal year
93
days that reach 90° in a normal year

Freezing nights by month

Average nights at or below 32°

90° days by month

Average days at 90° or more
Heating & cooling

Heating and cooling a home in San Antonio Heights

Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In San Antonio Heights, 40% of that work is heating and 60% is cooling, so air conditioning is the bigger bill.

40%heating
1,293 heating degree daysLess heating than 96% of U.S. towns
1,970 cooling degree daysMore cooling than 88% of U.S. towns

Degree days measure how far each day’s average temperature falls below or rises above 65°, added up over a year. Source: NOAA station normals.

Around San Antonio Heights

San Antonio Heights and its neighbors

San Antonio Heights borders 3 towns with climate data. January nights across them vary by 1.8°. Upland has the coldest January nights (44°) and Rancho Cucamonga the hottest July afternoons (93°). San Antonio Heights’s January low is 46° and its July high 92°.

Ontario: January low 43°, July high 92°Montclair: January low 43°, July high 92°Fontana: January low 43°, July high 94°Pomona: January low 44°, July high 90°La Verne: January low 44°, July high 91°Upland: January low 44°, July high 92°Rancho Cucamonga: January low 44°, July high 93°Claremont: January low 44°, July high 91°San Antonio Heights: January low 46°, July high 92° San Antonio HeightsUplandRancho CucamongaClaremont
ColderMilder43° to 46°
Upland43.8° −1.8°
Rancho Cucamonga43.8° −1.8°
Claremont44.0° −1.6°
San Antonio Heights45.6°

Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.

Compared with other towns

How San Antonio Heights compares

Summer heat92° July high
Hotter than 89% of U.S. towns676th hottest of 1,618 California towns
Winter cold46° January low
Milder than 97% of U.S. towns165th mildest of 1,618 California towns
Precipitation20" a year
Drier than 88% of U.S. towns665th wettest of 1,618 California towns
Snow0.0" a winter
Less snow than 96% of U.S. towns470th snowiest of 1,499 California towns

Compared with every U.S. town and city on TownTapestry, each counted once.

Then and now

Warmer than it used to be

+2.5°1991–2020 average vs. the 20th century (1901–2000)

The last 30 years in San Antonio Heights averaged 2.5° warmer than the 1900s. The biggest change is in January (+3.5°). The shift is larger than in 100% of U.S. towns.

❄️ Winter+2.5° now 55°, was 53°
🌷 Spring+2.6° now 61°, was 59°
☀️ Summer+2.5° now 76°, was 74°
🍂 Fall+2.6° now 69°, was 66°

Change by month1991–2020 average minus 1901–2000 average, at San Antonio Heights’s spot on NOAA’s grid

Year to year

How much a month can swing

A normal is an average, and real years wander around it. February swings the most: between 1991 and 2020 its average temperature ranged from 48° to 65°. August is the most reliable, staying within 7°.

Coldest to warmest month in 30 yearsNormal
Questions

Common questions about San Antonio Heights’s climate

What is the coldest month in San Antonio Heights?

December, with a typical high of 65° and a low of 44°.

What is the hottest month in San Antonio Heights?

August, with a typical high of 94° and a low of 65°. About 93 days a year reach 90°.

How much snow does San Antonio Heights get?

Almost none. A normal year brings 0.0 inches.

When is the first frost in San Antonio Heights?

Frost is uncommon. Only 41% of years see a night at 32° or below.

What is the rainiest month in San Antonio Heights?

February, with 5.1 inches of rain and melted snow. The year totals 20 inches.

Temperatures and rainfall come from NOAA’s gridded climate normals for San Antonio Heights itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Glendora Fc 287b, CA (11 mi, snow) and Ontario Intl Airport, CA (8 mi, frost, heat and degree days). Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.

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Boundary source: https://tigerweb.geo.census.gov/arcgis/rest/services/TIGERweb/Places_CouSub_ConCity_SubMCD/MapServer/19 · 2025-01-01