Antioch, California climate: Normal weather by month, frost dates and records
Antioch's normal year runs from 40°F January nights to 91°F July afternoons, with 12.6 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 16.9°C, January lows of 5°C, July highs of 33°C, 320 mm of precipitation a year.
- NOAA stationAntioch Pumping Plant #3
- Station IDUSC00040232
- Location37.98°N 121.75°W
- Elevation60 ft (18 m)
- From the center2 miles
- Population118,453
On October 14, the normal high in Antioch is 78°F and the normal low 55°F, and the chance of measurable rain or snow is 4%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Antioch.
- Jan 56° 40°
- Feb 61° 44°
- Mar 67° 47°
- Apr 72° 50°
- May 79° 54°
- Jun 86° 59°
- Jul 91° 61°
- Aug 90° 60°
- Sep 87° 59°
- Oct 78° 54°
- Nov 65° 46°
- Dec 56° 40°
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 Antioch each month?
July is the warmest month, with normal highs of 91°F; January the coldest, with normal lows of 40°F. The most precipitation falls in January (2.68 in), the least in July (0.00 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 | 56°F | 40°F | 48.0°F | 2.68 | 11 | <1 | 4 | 9 h 50 min |
| February | 61°F | 44°F | 52.3°F | 2.36 | 9 | <1 | <1 | 10 h 50 min |
| March | 67°F | 47°F | 56.5°F | 1.95 | 8 | <1 | <1 | 11 h 50 min |
| April | 72°F | 50°F | 60.8°F | 0.91 | 4 | <1 | <1 | 13 h 10 min |
| May | 79°F | 54°F | 66.6°F | 0.38 | 3 | 4 | <1 | 14 h 10 min |
| June | 86°F | 59°F | 72.6°F | 0.11 | 1 | 11 | <1 | 14 h 50 min |
| July | 91°F | 61°F | 76.0°F | 0.00 | <1 | 20 | <1 | 14 h 30 min |
| August | 90°F | 60°F | 75.2°F | 0.02 | <1 | 16 | <1 | 13 h 40 min |
| September | 87°F | 59°F | 72.7°F | 0.06 | <1 | 11 | <1 | 12 h 30 min |
| October | 78°F | 54°F | 65.9°F | 0.42 | 1 | 2 | <1 | 11 h 20 min |
| November | 65°F | 46°F | 55.4°F | 1.18 | 5 | <1 | <1 | 10 h 10 min |
| December | 56°F | 40°F | 48.1°F | 2.53 | 9 | <1 | 3 | 9 h 30 min |
| Year (annual) | 74°F | 51°F | 62.5°F | 12.60 | 50 | 64 | 7 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 13°C | 5°C | 8.9°C | 68 mm |
| February | 16°C | 7°C | 11.3°C | 60 mm |
| March | 19°C | 8°C | 13.6°C | 50 mm |
| April | 22°C | 10°C | 16.0°C | 23 mm |
| May | 26°C | 12°C | 19.2°C | 10 mm |
| June | 30°C | 15°C | 22.6°C | 3 mm |
| July | 33°C | 16°C | 24.4°C | 0 mm |
| August | 32°C | 16°C | 24.0°C | 1 mm |
| September | 30°C | 15°C | 22.6°C | 2 mm |
| October | 25°C | 12°C | 18.8°C | 11 mm |
| November | 18°C | 8°C | 13.0°C | 30 mm |
| December | 13°C | 5°C | 8.9°C | 64 mm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00040232; 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 Antioch?
Normal highs sit between 65°F and 85°F in March, April, May and October. Of those, October 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 USC00040232.
When is the last frost in Antioch?
In Antioch, the last spring frost (32°F) comes after January 12 in half of years and after February 1 in one year in ten; the first autumn frost comes before December 19 in half of years and before November 29 in one year in ten. A night at 32°F or colder comes at all in 81% 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 121 year in 10 after February 1; 9 in 10 after December 20
- First autumn frost, half of years before
- December 191 year in 10 before November 29; 9 in 10 before January 12
NOAA puts the median frost-free season at 343 days, and the season without a hard freeze (28°F) at 365 days.
A hard freeze (28°F) comes after January 2 in half of springs and before December 29 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Antioch in zone 9b across its 2 ZIP code areas (9b in 94509, the largest). By the map's own method, the average of each year's coldest night over 1991-2020, Antioch's NOAA station is in zone 9b: the coldest night of a typical year reaches 29°F (18 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 USC00040232; 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 Antioch ZIP code in?
The USDA's 2023 map gives each ZIP code area one zone. Antioch's 2 ZIP code areas are all in zone 9b. 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 Antioch?
In a normal year in Antioch, 64 days a year reach 90°F (10 of them 100°F or more), 7 nights fall to 32°F or colder and 50 days bring measurable precipitation.
- Days at 90°F or more
- 64a normal year
- Days at 100°F or more
- 10a normal year
- Nights at 32°F or colder
- 7a normal year
- Days that stay below freezing
- fewer than 1high of 32°F or less
- Days with 0.01 inch of precipitation
- 50a normal year
The highest temperature in this station's record (since 1955) is 117°F, on June 17, 1961; the lowest is 18°F, on December 12, 1972.
The wettest calendar year on that record is 1958, with 18.38 in.
Source: NOAA NCEI 1991-2020 annual normals, station USC00040232; records: ACIS (NOAA Regional Climate Centers), station USC00040232. Records use complete months only; a month missing more than three days is left out.
How sunny is Antioch?
Over a year 89% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Antioch, 5.3 kWh per square metre a day. July is the sunniest month (97%) and January the cloudiest (74%). Among the 459 U.S. places of 50,000 or more, that ranks tied 39th (with 12 others) in sunshine.
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 74% | 2.4 |
| February | 78% | 3.5 |
| March | 81% | 4.8 |
| April | 85% | 6.2 |
| May | 90% | 7.5 |
| June | 95% | 8.3 |
| July | 97% | 8.2 |
| August | 97% | 7.4 |
| September | 95% | 6.0 |
| October | 91% | 4.4 |
| November | 83% | 2.9 |
| December | 74% | 2.2 |
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 Antioch need?
A normal year in Antioch brings 2,230 heating degree days, 59% fewer than the median U.S. place (5,373), and 1,345 cooling degree days, 48% more than the median (908). Three months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 4,827 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 527 | 0 |
| February | 354 | 0 |
| March | 264 | 2 |
| April | 150 | 24 |
| May | 52 | 103 |
| June | 6 | 236 |
| July | 0 | 341 |
| August | 0 | 318 |
| September | 4 | 235 |
| October | 58 | 84 |
| November | 291 | 3 |
| December | 524 | 0 |
| Year (annual) | 2,230 | 1,345 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00040232. 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.
How does Antioch's climate compare?
Antioch is warmer than 129 of the other 218 places with their own NOAA record in California, and wetter than 72. Across the 7,247 U.S. stations with normals, its annual mean of 62.5°F is warmer than 81%.
In the Köppen classification computed from these normals, Antioch is BSk: cold 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 Antioch share this climate record?
9 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.
- Pittsburg, CAalso near: Concord (9 mi, 62.0°F a year); Concord Wastewater Treatment Plant (10 mi, 62.4°F a year)77,131 people · 8 mi W
- Brentwood, CAalso near: Mount Diablo Junction (12 mi, 58.4°F a year); Livermore (18 mi, 59.8°F a year)66,286 people · 4 mi SE
- Oakley, CA47,158 people · 3 mi E
- Discovery Bay, CA15,243 people · 10 mi SE
- Rio Vista, CA10,248 people · 14 mi N
- Bethel Island, CA2,144 people · 7 mi NE
- Knightsen, CA2,018 people · 6 mi E
- Byron, CA1,876 people · 10 mi SE
- Isleton, CA781 people · 15 mi NE
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 Antioch's climate
What is the coldest month in Antioch?
January, with a normal high of 56°F and a normal low of 40°F. The warmest is July (91°F by day, 61°F at night).
Does it snow in Antioch?
Rarely: NOAA's normal is no measurable snow a year.
What is the rainiest month in Antioch?
January, with 2.68 in of precipitation in a normal year; the driest is July with 0.00 in.
What plant hardiness zone is Antioch in?
The USDA's 2023 map puts Antioch in zone 9b across its 2 ZIP code areas (9b in 94509, the largest). By the same method at Antioch's NOAA station, the coldest night of a typical year reaches 29°F (18 years, 1991-2020): zone 9b.
How late can frost come in Antioch?
In half of years the last 32°F night comes after January 12; in one year in ten it comes after February 1. Waiting until February 1 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Antioch in OctoberThis month day by day, its records and recent years
- California climateThe statewide normals and every place in the state
- Mount Diablo Junction, CA12 miles from this station, 58.4°F a year
- Concord, CA17 miles from this station, 62.0°F a year
- Concord Wastewater Treatment Plant, CA17 miles from this station, 62.4°F a year
- Martinez, CA20 miles from this station, 58.2°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made