Modesto, California climate: Normal weather by month, frost dates and records
Modesto's normal year runs from 39°F December nights to 95°F July afternoons, with 12.3 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 17.3°C, December lows of 4°C, July highs of 35°C, 312 mm of precipitation a year.
- NOAA stationModesto City County Airport
- Station IDUSW00023258
- Location37.62°N 120.95°W
- Elevation73 ft (22 m)
- From the center3 miles
- Population220,592
On October 14, the normal high in Modesto is 80°F and the normal low 52°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 Modesto.
- Jan 56° 39°
- Feb 62° 42°
- Mar 68° 45°
- Apr 74° 48°
- May 82° 54°
- Jun 90° 59°
- Jul 95° 63°
- Aug 94° 62°
- Sep 89° 59°
- Oct 79° 52°
- Nov 66° 43°
- Dec 56° 39°
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 Modesto each month?
July is the warmest month, with normal highs of 95°F; December the coldest, with normal lows of 39°F. The most precipitation falls in January (2.57 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 | 39°F | 47.5°F | 2.57 | 10 | <1 | 5 | 9 h 50 min |
| February | 62°F | 42°F | 52.0°F | 2.22 | 9 | <1 | 1 | 10 h 50 min |
| March | 68°F | 45°F | 56.7°F | 1.78 | 8 | <1 | <1 | 11 h 50 min |
| April | 74°F | 48°F | 61.1°F | 1.00 | 5 | 1 | <1 | 13 h 10 min |
| May | 82°F | 54°F | 67.8°F | 0.65 | 3 | 7 | <1 | 14 h 10 min |
| June | 90°F | 59°F | 74.5°F | 0.15 | 1 | 16 | <1 | 14 h 40 min |
| July | 95°F | 63°F | 78.8°F | 0.00 | <1 | 26 | <1 | 14 h 30 min |
| August | 94°F | 62°F | 77.8°F | 0.01 | <1 | 23 | <1 | 13 h 40 min |
| September | 89°F | 59°F | 73.9°F | 0.06 | <1 | 15 | <1 | 12 h 30 min |
| October | 79°F | 52°F | 65.2°F | 0.55 | 2 | 3 | <1 | 11 h 20 min |
| November | 66°F | 43°F | 54.5°F | 1.07 | 6 | <1 | 1 | 10 h 10 min |
| December | 56°F | 39°F | 47.4°F | 2.21 | 9 | <1 | 6 | 9 h 40 min |
| Year (annual) | 76°F | 50°F | 63.1°F | 12.27 | 53 | 90 | 12 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 13°C | 4°C | 8.6°C | 65 mm |
| February | 17°C | 5°C | 11.1°C | 56 mm |
| March | 20°C | 7°C | 13.7°C | 45 mm |
| April | 23°C | 9°C | 16.2°C | 25 mm |
| May | 28°C | 12°C | 19.9°C | 17 mm |
| June | 32°C | 15°C | 23.6°C | 4 mm |
| July | 35°C | 17°C | 26.0°C | 0 mm |
| August | 34°C | 17°C | 25.4°C | 0 mm |
| September | 32°C | 15°C | 23.3°C | 2 mm |
| October | 26°C | 11°C | 18.4°C | 14 mm |
| November | 19°C | 6°C | 12.5°C | 27 mm |
| December | 13°C | 4°C | 8.6°C | 56 mm |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00023258; 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 Modesto?
Normal highs sit between 65°F and 85°F in March, April, May, October and November. Of those, October has the fewest days with rain (2).
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 USW00023258.
When is the last frost in Modesto?
In Modesto, the last spring frost (32°F) comes after January 31 in half of years and after February 25 in one year in ten; the first autumn frost comes before December 5 in half of years and before November 20 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- January 311 year in 10 after February 25; 9 in 10 after December 31
- First autumn frost, half of years before
- December 51 year in 10 before November 20; 9 in 10 before January 6
NOAA puts the median frost-free season at 312 days, and the season without a hard freeze (28°F) at 352 days.
A hard freeze (28°F) comes after January 8 in half of springs and before December 21 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Modesto in zone 9b across its 5 ZIP code areas (9b in 95355, the largest). By the map's own method, the average of each year's coldest night over 1991-2020, Modesto's NOAA station is in zone 9b: the coldest night of a typical year reaches 28°F (30 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 USW00023258; 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 Modesto ZIP code in?
The USDA's 2023 map gives each ZIP code area one zone. Modesto's 5 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 Modesto?
In a normal year in Modesto, 90 days a year reach 90°F (18 of them 100°F or more), 12 nights fall to 32°F or colder and 53 days bring measurable precipitation.
- Days at 90°F or more
- 90a normal year
- Days at 100°F or more
- 18a normal year
- Nights at 32°F or colder
- 12a normal year
- Days that stay below freezing
- fewer than 1high of 32°F or less
- Days with 0.01 inch of precipitation
- 53a normal year
The highest temperature in this station's record (since 1927) is 113°F, on July 24, 2006; the lowest is 18°F, on January 11, 1949.
The wettest calendar year on that record is 1998, with 23.27 in; the snowiest season is 1961–62, with 1.5 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USW00023258; records: ACIS (NOAA Regional Climate Centers), station USW00023258. Records use complete months only; a month missing more than three days is left out.
How sunny is Modesto?
Over a year 90% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Modesto, 5.3 kWh per square metre a day. July is the sunniest month (98%) and January the cloudiest (71%). 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 | 71% | 2.3 |
| February | 78% | 3.5 |
| March | 82% | 4.9 |
| April | 86% | 6.3 |
| May | 92% | 7.6 |
| June | 96% | 8.4 |
| July | 98% | 8.2 |
| August | 98% | 7.4 |
| September | 96% | 6.0 |
| October | 92% | 4.4 |
| November | 82% | 2.9 |
| December | 72% | 2.1 |
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 Modesto need?
A normal year in Modesto brings 2,300 heating degree days, 57% fewer than the median U.S. place (5,373), and 1,624 cooling degree days, 79% more than the median (908). Four months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 5,078 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 544 | 0 |
| February | 364 | 0 |
| March | 262 | 3 |
| April | 146 | 29 |
| May | 44 | 133 |
| June | 5 | 288 |
| July | 0 | 429 |
| August | 0 | 395 |
| September | 4 | 269 |
| October | 68 | 75 |
| November | 318 | 2 |
| December | 546 | 0 |
| Year (annual) | 2,300 | 1,624 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00023258. 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 Modesto been warmer than normal lately?
2024 averaged 64.9°F, 1.8°F above the 1991-2020 normal of 63.1°F. 2 of the 4 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 62.9°F | −0.2°F | 13.76 |
| 2022 | 63.3°F | +0.2°F | 9.06 |
| 2023 | 61.9°F | −1.2°F | 15.85 |
| 2024 | 64.9°F | +1.8°F | 17.41 |
Over 79 complete years from 1931 to 2025, the station's annual mean temperature rose at a fitted 4.3°F per century (+0.24°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USW00023258; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Modesto's climate compare?
Modesto is warmer than 151 of the other 218 places with their own NOAA record in California, and wetter than 68. Across the 7,247 U.S. stations with normals, its annual mean of 63.1°F is warmer than 83%.
In the Köppen classification computed from these normals, Modesto 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 Modesto share this climate record?
22 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.
- Ceres, CA49,253 people · 2 mi SW
- Riverbank, CA25,625 people · 7 mi N
- Patterson, CA25,495 people · 15 mi SW
- Oakdale, CA23,209 people · 11 mi NE
- Salida, CA14,457 people · 9 mi NW
- Waterford, CA9,271 people · 11 mi E
- Hughson, CA7,903 people · 5 mi E
- Escalon, CA7,453 people · 12 mi N
- West Modesto, CA5,633 people · 5 mi W
- Keyes, CA5,330 people · 5 mi SE
- Bret Harte, CA4,807 people · 3 mi SW
- Bystrom, CA4,109 people · 2 mi W
- Empire, CA3,867 people · 3 mi NE
- East Oakdale, CA2,346 people · 14 mi NE
- Parklawn, CA1,574 people · 2 mi SW
- Del Rio, CA1,557 people · 9 mi N
- Airport, CA1,258 people · 1 mi NW
- Rouse, CA1,205 people · 3 mi W
- Riverdale Park, CA998 people · 5 mi W
- Cowan, CA497 people · 5 mi SW
- Valley Home, CA208 people · 14 mi N
- Monterey Park Tract, CA144 people · 8 mi SW
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 Modesto's climate
What is the coldest month in Modesto?
December, with a normal high of 56°F and a normal low of 39°F. The warmest is July (95°F by day, 63°F at night).
What is the rainiest month in Modesto?
January, with 2.57 in of precipitation in a normal year; the driest is July with 0.00 in.
What plant hardiness zone is Modesto in?
The USDA's 2023 map puts Modesto in zone 9b across its 5 ZIP code areas (9b in 95355, the largest). By the same method at Modesto's NOAA station, the coldest night of a typical year reaches 28°F (30 years, 1991-2020): zone 9b.
How late can frost come in Modesto?
In half of years the last 32°F night comes after January 31; in one year in ten it comes after February 25. Waiting until February 25 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Modesto in OctoberThis month day by day, its records and recent years
- California climateThe statewide normals and every place in the state
- Turlock, CA10 miles from this station, 64.0°F a year
- Tracy, CA22 miles from this station, 61.0°F a year
- Stockton, CA24 miles from this station, 63.0°F a year
- Newman, CA24 miles from this station, 65.0°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made