El Cajon, California climate: Normal weather by month, frost dates and records
El Cajon's normal year runs from 42°F December nights to 89°F August afternoons, with 11.6 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 18.4°C, December lows of 5°C, August highs of 31°C, 295 mm of precipitation a year.
- NOAA stationEl Cajon
- Station IDUSC00042706
- Location32.80°N 116.93°W
- Elevation495 ft (151 m)
- From the center2 miles
- Population103,291
On October 23, the normal high in El Cajon is 80°F and the normal low 54°F, and the chance of measurable rain or snow is 7%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for El Cajon.
- Jan 69° 43°
- Feb 69° 44°
- Mar 71° 48°
- Apr 75° 51°
- May 76° 56°
- Jun 81° 59°
- Jul 86° 63°
- Aug 89° 65°
- Sep 87° 62°
- Oct 81° 56°
- Nov 75° 47°
- Dec 69° 42°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in El Cajon each month?
August is the warmest month, with normal highs of 89°F; December the coldest, with normal lows of 42°F. The most precipitation falls in February (2.61 in), the least in August (0.02 in).
Each month has its own page with the day-by-day normals, the month's records and its recent years:
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 69°F | 43°F | 55.9°F | 2.32 | 6 | <1 | 1 | 10 h 10 min |
| February | 69°F | 44°F | 56.8°F | 2.61 | 7 | <1 | <1 | 11 h |
| March | 71°F | 48°F | 59.7°F | 1.92 | 5 | 1 | <1 | 12 h |
| April | 75°F | 51°F | 62.6°F | 0.75 | 4 | 2 | <1 | 13 h |
| May | 76°F | 56°F | 66.1°F | 0.30 | 2 | 3 | <1 | 13 h 50 min |
| June | 81°F | 59°F | 70.1°F | 0.06 | 1 | 4 | <1 | 14 h 20 min |
| July | 86°F | 63°F | 74.7°F | 0.16 | 1 | 10 | <1 | 14 h 10 min |
| August | 89°F | 65°F | 76.6°F | 0.02 | <1 | 15 | <1 | 13 h 20 min |
| September | 87°F | 62°F | 74.7°F | 0.11 | 1 | 14 | <1 | 12 h 30 min |
| October | 81°F | 56°F | 68.3°F | 0.54 | 2 | 7 | <1 | 11 h 30 min |
| November | 75°F | 47°F | 61.2°F | 1.01 | 3 | 2 | <1 | 10 h 30 min |
| December | 69°F | 42°F | 55.1°F | 1.83 | 6 | <1 | 1 | 10 h |
| Year (annual) | 77°F | 53°F | 65.2°F | 11.63 | 36 | 57 | 3 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 21°C | 6°C | 13.3°C | 59 mm |
| February | 21°C | 7°C | 13.8°C | 66 mm |
| March | 22°C | 9°C | 15.4°C | 49 mm |
| April | 24°C | 10°C | 17.0°C | 19 mm |
| May | 25°C | 13°C | 18.9°C | 8 mm |
| June | 27°C | 15°C | 21.2°C | 2 mm |
| July | 30°C | 17°C | 23.7°C | 4 mm |
| August | 31°C | 18°C | 24.8°C | 1 mm |
| September | 31°C | 17°C | 23.7°C | 3 mm |
| October | 27°C | 13°C | 20.2°C | 14 mm |
| November | 24°C | 8°C | 16.2°C | 26 mm |
| December | 20°C | 5°C | 12.8°C | 46 mm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00042706; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit El Cajon?
Normal highs sit between 65°F and 85°F in January, February, March, April, May, June, October, November and December. Of those, June has the fewest days with rain (1).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00042706.
When is the last frost in El Cajon?
In El Cajon, the last spring frost (32°F) comes after January 6 in half of years and after February 7 in one year in ten; the first autumn frost comes before December 21 in half of years and before December 1 in one year in ten. A night at 32°F or colder comes at all in 73% of years here (NOAA).
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- January 61 year in 10 after February 7; 9 in 10 after December 13
- First autumn frost, half of years before
- December 211 year in 10 before December 1; 9 in 10 before January 15
NOAA puts the median frost-free season at 350 days, and the season without a hard freeze (28°F) at 365 days.
A hard freeze (28°F) comes after December 31 in half of springs and before December 30 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts El Cajon in zone 10a across its 2 ZIP code areas (10a in 92020, the largest). By the map's own method, the average of each year's coldest night over 1991-2020, El Cajon's NOAA station is in zone 10a: the coldest night of a typical year reaches 32°F (19 complete years).
Frost dates for every NOAA station in California · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00042706; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
What hardiness zone is each El Cajon ZIP code in?
The USDA's 2023 map gives each ZIP code area one zone. El Cajon's 2 ZIP code areas are all in zone 10a. Each ZIP's frost dates are in the frost tool.
Source: USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; ZIP areas in the place: Census Bureau 2020 ZCTA-to-place relationship file. A ZIP area counts when at least a tenth of its land (and 0.5 km²) lies in the place.
How hot and how cold does it get in El Cajon?
In a normal year in El Cajon, 57 days a year reach 90°F (7 of them 100°F or more), 3 nights fall to 32°F or colder and 36 days bring measurable precipitation.
- Days at 90°F or more
- 57a normal year
- Days at 100°F or more
- 7a normal year
- Nights at 32°F or colder
- 3a normal year
- Days that stay below freezing
- fewer than 1high of 32°F or less
- Days with 0.01 inch of precipitation
- 36a normal year
The highest temperature in El Cajon's official record (kept by the National Weather Service since 1899) is 114°F, on September 5, 2020; the lowest is 19°F, on January 8, 1913.
The wettest calendar year on that record is 1927, with 24.55 in.
Source: NOAA NCEI 1991-2020 annual normals, station USC00042706; records: ACIS (NOAA Regional Climate Centers), NWS threaded record ELJC1thr. Records use complete months only; a month missing more than three days is left out.
How sunny is El Cajon?
Over a year 90% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around El Cajon, 5.8 kWh per square metre a day. June is the sunniest month (94%) and February the cloudiest (83%). Among the 459 U.S. places of 50,000 or more, that ranks tied 21st (with 17 others) in sunshine.
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 85% | 3.5 |
| February | 83% | 4.3 |
| March | 87% | 5.7 |
| April | 89% | 7.0 |
| May | 90% | 7.7 |
| June | 94% | 8.3 |
| July | 92% | 7.7 |
| August | 94% | 7.3 |
| September | 93% | 6.3 |
| October | 91% | 5.0 |
| November | 88% | 3.8 |
| December | 84% | 3.1 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does El Cajon need?
A normal year in El Cajon brings 1,309 heating degree days, 76% fewer than the median U.S. place (5,373), and 1,377 cooling degree days, 52% more than the median (908). One month needs 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 5,564 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 283 | 1 |
| February | 232 | 2 |
| March | 176 | 10 |
| April | 100 | 28 |
| May | 42 | 75 |
| June | 4 | 157 |
| July | 0 | 301 |
| August | 0 | 361 |
| September | 1 | 292 |
| October | 25 | 127 |
| November | 139 | 23 |
| December | 307 | 1 |
| Year (annual) | 1,309 | 1,377 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00042706. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
Has El Cajon been warmer than normal lately?
2025 averaged 65.2°F, equal to the 1991-2020 normal of 65.2°F. 2 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 65.6°F | +0.4°F | 10.85 |
| 2022 | 65.3°F | +0.1°F | 7.97 |
| 2023 | 63.6°F | −1.6°F | 19.65 |
| 2024 | 64.6°F | −0.6°F | 14.97 |
| 2025 | 65.2°F | at normal | 10.75 |
Source: observed years: ACIS, station USC00042706. A year counts only with all twelve months complete.
How does El Cajon's climate compare?
El Cajon is warmer than 185 of the other 218 places with their own NOAA record in California, and wetter than 51. Across the 7,247 U.S. stations with normals, its annual mean of 65.2°F is warmer than 88%.
In the Köppen classification computed from these normals, El Cajon is BSh: hot semi-arid steppe. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near El Cajon share this climate record?
12 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- La Mesa, CAalso near: San Diego Montgomery Field (8 mi, 64.1°F a year); San Diego Miramar Naval Air Station (9 mi, 64.2°F a year)60,767 people · 6 mi W
- Santee, CAalso near: San Diego Miramar Naval Air Station (9 mi, 64.2°F a year); San Diego Montgomery Field (9 mi, 64.1°F a year)59,104 people · 5 mi NW
- Spring Valley, CA32,215 people · 6 mi SW
- Rancho San Diego, CA22,264 people · 3 mi S
- Winter Gardens, CA22,003 people · 3 mi N
- Lakeside, CA21,788 people · 4 mi N
- Casa de Oro-Mount Helix, CA19,651 people · 3 mi SW
- Bostonia, CA16,545 people · 1 mi NW
- Jamul, CA6,617 people · 7 mi SE
- Eucalyptus Hills, CA5,976 people · 6 mi N
- Granite Hills, CA3,867 people · 1 mi E
- Crest, CA3,034 people · 4 mi E
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about El Cajon's climate
What is the coldest month in El Cajon?
December, with a normal high of 69°F and a normal low of 42°F. The warmest is August (89°F by day, 65°F at night).
Does it snow in El Cajon?
Rarely: NOAA's normal is no measurable snow a year.
What is the rainiest month in El Cajon?
February, with 2.61 in of precipitation in a normal year; the driest is August with 0.02 in.
What plant hardiness zone is El Cajon in?
The USDA's 2023 map puts El Cajon in zone 10a across its 2 ZIP code areas (10a in 92020, the largest). By the same method at El Cajon's NOAA station, the coldest night of a typical year reaches 32°F (19 years, 1991-2020): zone 10a.
How late can frost come in El Cajon?
In half of years the last 32°F night comes after January 6; in one year in ten it comes after February 7. Waiting until February 7 leaves about a one-in-ten chance of a later frost.
Nearby and next
- El Cajon in OctoberThis month day by day, its records and recent years
- California climateThe statewide normals and every place in the state
- El Capitan Dam, CA9 miles from this station, 65.4°F a year
- Alpine, CA9 miles from this station, 62.6°F a year
- San Diego Montgomery Field, CA12 miles from this station, 64.1°F a year
- San Diego Miramar Naval Air Station, CA13 miles from this station, 64.2°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made