Healdsburg, California climate: Normal weather by month, frost dates and records
Healdsburg's normal year runs from 39°F December nights to 89°F July afternoons, with 42.8 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 15.7°C, December lows of 4°C, July highs of 32°C, 1,087 mm of precipitation a year.
- NOAA stationHealdsburg
- Station IDUSC00043875
- Location38.63°N 122.87°W
- Elevation177 ft (54 m)
- From the centerunder 1 mile
- Population11,231
On October 24, the normal high in Healdsburg is 75°F and the normal low 47°F, and the chance of measurable rain or snow is 15%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Healdsburg.
- Jan 58° 39°
- Feb 62° 41°
- Mar 66° 43°
- Apr 72° 45°
- May 79° 50°
- Jun 86° 54°
- Jul 89° 54°
- Aug 88° 54°
- Sep 85° 52°
- Oct 77° 49°
- Nov 65° 43°
- Dec 57° 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 Healdsburg each month?
July is the warmest month, with normal highs of 89°F; December the coldest, with normal lows of 39°F. The most precipitation falls in December (8.51 in), the least in July (0.00 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 58°F | 39°F | 48.5°F | 8.00 | 14 | <1 | 4 | 9 h 40 min |
| February | 62°F | 41°F | 51.3°F | 8.33 | 12 | <1 | 2 | 10 h 40 min |
| March | 66°F | 43°F | 54.4°F | 6.35 | 12 | <1 | 1 | 11 h 50 min |
| April | 72°F | 45°F | 58.6°F | 2.87 | 8 | 1 | <1 | 13 h 10 min |
| May | 79°F | 50°F | 64.3°F | 1.60 | 5 | 5 | <1 | 14 h 10 min |
| June | 86°F | 54°F | 69.7°F | 0.35 | 1 | 11 | <1 | 14 h 50 min |
| July | 89°F | 54°F | 71.5°F | 0.00 | <1 | 15 | <1 | 14 h 40 min |
| August | 88°F | 54°F | 71.0°F | 0.04 | <1 | 15 | <1 | 13 h 40 min |
| September | 85°F | 52°F | 68.5°F | 0.10 | 1 | 9 | <1 | 12 h 30 min |
| October | 77°F | 49°F | 62.7°F | 2.20 | 4 | 3 | <1 | 11 h 20 min |
| November | 65°F | 43°F | 53.8°F | 4.46 | 8 | <1 | 2 | 10 h 10 min |
| December | 57°F | 39°F | 48.0°F | 8.51 | 13 | <1 | 5 | 9 h 30 min |
| Year (annual) | 74°F | 47°F | 60.2°F | 42.81 | 77 | 58 | 13 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 14°C | 4°C | 9.2°C | 203 mm |
| February | 16°C | 5°C | 10.7°C | 212 mm |
| March | 19°C | 6°C | 12.4°C | 161 mm |
| April | 22°C | 7°C | 14.8°C | 73 mm |
| May | 26°C | 10°C | 17.9°C | 41 mm |
| June | 30°C | 12°C | 20.9°C | 9 mm |
| July | 32°C | 12°C | 21.9°C | 0 mm |
| August | 31°C | 12°C | 21.7°C | 1 mm |
| September | 29°C | 11°C | 20.3°C | 3 mm |
| October | 25°C | 9°C | 17.1°C | 56 mm |
| November | 18°C | 6°C | 12.1°C | 113 mm |
| December | 14°C | 4°C | 8.9°C | 216 mm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00043875; 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 Healdsburg?
Normal highs sit between 65°F and 85°F in March, April, May, September and October. Of those, September 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 USC00043875.
When is the last frost in Healdsburg?
In Healdsburg, the last spring frost (32°F) comes after February 15 in half of years and after March 17 in one year in ten; the first autumn frost comes before December 2 in half of years and before November 14 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
- February 151 year in 10 after March 17; 9 in 10 after January 4
- First autumn frost, half of years before
- December 21 year in 10 before November 14; 9 in 10 before January 1
NOAA puts the median frost-free season at 292 days, and the season without a hard freeze (28°F) at 347 days.
A hard freeze (28°F) comes after January 7 in half of springs and before December 17 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Healdsburg in zone 9b in ZIP code 95448, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Healdsburg's NOAA station is in zone 9b: the coldest night of a typical year reaches 27°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 USC00043875; 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.
How hot and how cold does it get in Healdsburg?
In a normal year in Healdsburg, 58 days a year reach 90°F (11 of them 100°F or more), 13 nights fall to 32°F or colder and 77 days bring measurable precipitation.
- Days at 90°F or more
- 58a normal year
- Days at 100°F or more
- 11a normal year
- Nights at 32°F or colder
- 13a normal year
- Days that stay below freezing
- fewer than 1high of 32°F or less
- Days with 0.01 inch of precipitation
- 77a normal year
The highest temperature in this station's record (since 1897) is 117°F, on September 6, 2022; the lowest is 14°F, on December 22, 1990.
The wettest calendar year on that record is 1983, with 96.25 in.
Source: NOAA NCEI 1991-2020 annual normals, station USC00043875; records: ACIS (NOAA Regional Climate Centers), station USC00043875. Records use complete months only; a month missing more than three days is left out.
How sunny is Healdsburg?
Over a year 87% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Healdsburg, 5.1 kWh per square metre a day. July is the sunniest month (95%) and December the cloudiest (72%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 74% | 2.3 |
| February | 77% | 3.3 |
| March | 78% | 4.6 |
| April | 84% | 6.1 |
| May | 88% | 7.3 |
| June | 93% | 8.1 |
| July | 95% | 8.0 |
| August | 94% | 7.1 |
| September | 93% | 5.8 |
| October | 88% | 4.2 |
| November | 81% | 2.8 |
| December | 72% | 2.0 |
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 Healdsburg need?
A normal year in Healdsburg brings 2,524 heating degree days, 53% fewer than the median U.S. place (5,373), and 781 cooling degree days, 14% fewer than the median (908). Five months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 3,988 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 512 | 0 |
| February | 385 | 0 |
| March | 332 | 1 |
| April | 203 | 11 |
| May | 84 | 60 |
| June | 15 | 158 |
| July | 2 | 204 |
| August | 3 | 189 |
| September | 15 | 119 |
| October | 109 | 38 |
| November | 337 | 1 |
| December | 527 | 0 |
| Year (annual) | 2,524 | 781 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00043875. 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 Healdsburg been warmer than normal lately?
2025 averaged 60.3°F, 0.1°F above the 1991-2020 normal of 60.2°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 60.7°F | +0.5°F | 35.17 |
| 2022 | 61.0°F | +0.8°F | 19.64 |
| 2023 | 59.4°F | −0.8°F | 52.37 |
| 2024 | 61.4°F | +1.2°F | 60.12 |
| 2025 | 60.3°F | +0.1°F | 36.96 |
Over 74 complete years from 1901 to 2025, the station's annual mean temperature rose at a fitted 3.0°F per century (+0.17°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00043875; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Healdsburg's climate compare?
Healdsburg is warmer than 99 of the other 218 places with their own NOAA record in California, and wetter than 191. Across the 7,247 U.S. stations with normals, its annual mean of 60.2°F is warmer than 75%.
In the Köppen classification computed from these normals, Healdsburg is Csb: temperate, dry-summer, warm summer. 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 Healdsburg share this climate record?
Geyserville has no NOAA station with 1991-2020 normals of its 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.
- Geyserville, CA830 people · 6 mi N
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 Healdsburg's climate
What is the coldest month in Healdsburg?
December, with a normal high of 57°F and a normal low of 39°F. The warmest is July (89°F by day, 54°F at night).
Does it snow in Healdsburg?
Rarely: NOAA's normal is no measurable snow a year.
What is the rainiest month in Healdsburg?
December, with 8.51 in of precipitation in a normal year; the driest is July with 0.00 in.
What plant hardiness zone is Healdsburg in?
The USDA's 2023 map puts Healdsburg in zone 9b in ZIP code 95448, the nearest ZIP area. By the same method at Healdsburg's NOAA station, the coldest night of a typical year reaches 27°F (19 years, 1991-2020): zone 9b.
How late can frost come in Healdsburg?
In half of years the last 32°F night comes after February 15; in one year in ten it comes after March 17. Waiting until March 17 leaves about a one-in-ten chance of a later frost.
Nearby and next
- California climateThe statewide normals and every place in the state
- Santa Rosa, CA9 miles from this station, 58.1°F a year
- Graton, CA14 miles from this station, 57.8°F a year
- Cloverdale, CA14 miles from this station, 61.8°F a year
- Calistoga, CA14 miles from this station, 60.1°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made