Morro Bay, California climate: Normal weather by month, frost dates and records
Morro Bay's normal year runs from 46°F December nights to 72°F September afternoons, with 17.0 inches of precipitation and less than an inch of snow (0.1 in) a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 15.3°C, December lows of 8°C, September highs of 22°C, 432 mm of precipitation a year.
- NOAA stationMorro Bay Fire Dept
- Station IDUSC00045866
- Location35.37°N 120.84°W
- Elevation118 ft (36 m)
- Population10,591
On October 14, the normal high in Morro Bay is 73°F and the normal low 55°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 Morro Bay.
- Jan 65° 46°
- Feb 65° 48°
- Mar 66° 49°
- Apr 67° 49°
- May 67° 52°
- Jun 66° 54°
- Jul 67° 57°
- Aug 70° 57°
- Sep 72° 56°
- Oct 73° 54°
- Nov 69° 50°
- Dec 65° 46°
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 Morro Bay each month?
September is the warmest month, with normal highs of 72°F; December the coldest, with normal lows of 46°F. The most precipitation falls in January (3.64 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 | 65°F | 46°F | 55.7°F | 3.64 | 7 | <1 | 1 | 10 h |
| February | 65°F | 48°F | 56.6°F | 3.62 | 8 | <1 | <1 | 10 h 50 min |
| March | 66°F | 49°F | 57.3°F | 3.19 | 7 | <1 | <1 | 11 h 50 min |
| April | 67°F | 49°F | 58.3°F | 0.99 | 4 | <1 | <1 | 13 h |
| May | 67°F | 52°F | 59.3°F | 0.42 | 2 | <1 | <1 | 14 h |
| June | 66°F | 54°F | 60.0°F | 0.20 | <1 | <1 | <1 | 14 h 30 min |
| July | 67°F | 57°F | 61.8°F | 0.07 | <1 | <1 | <1 | 14 h 20 min |
| August | 70°F | 57°F | 63.2°F | 0.02 | <1 | <1 | <1 | 13 h 30 min |
| September | 72°F | 56°F | 63.7°F | 0.09 | 1 | <1 | <1 | 12 h 30 min |
| October | 73°F | 54°F | 63.5°F | 0.68 | 2 | 1 | <1 | 11 h 20 min |
| November | 69°F | 50°F | 59.7°F | 1.33 | 3 | <1 | <1 | 10 h 20 min |
| December | 65°F | 46°F | 55.4°F | 2.75 | 7 | <1 | 1 | 9 h 50 min |
| Year (annual) | 68°F | 51°F | 59.5°F | 17.00 | 42 | 1 | 3 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 18°C | 8°C | 13.2°C | 92 mm |
| February | 19°C | 9°C | 13.7°C | 92 mm |
| March | 19°C | 9°C | 14.1°C | 81 mm |
| April | 20°C | 10°C | 14.6°C | 25 mm |
| May | 19°C | 11°C | 15.2°C | 11 mm |
| June | 19°C | 12°C | 15.6°C | 5 mm |
| July | 20°C | 14°C | 16.6°C | 2 mm |
| August | 21°C | 14°C | 17.3°C | 1 mm |
| September | 22°C | 13°C | 17.6°C | 2 mm |
| October | 23°C | 12°C | 17.5°C | 17 mm |
| November | 21°C | 10°C | 15.4°C | 34 mm |
| December | 18°C | 8°C | 13.0°C | 70 mm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00045866; 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 Morro Bay?
Normal highs sit between 65°F and 85°F in January, February, March, April, May, June, July, August, September, October and November. Of those, August has the fewest days with rain (0).
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 USC00045866.
When is the last frost in Morro Bay?
A night at 32°F or colder comes in only 15% of years in Morro Bay (NOAA). NOAA's median date of the last spring frost is January 19 and of the first autumn frost January 14.
NOAA puts the median frost-free season at 365 days, and the season without a hard freeze (28°F) at 365 days.
The USDA's 2023 Plant Hardiness Zone Map puts Morro Bay in zone 9b in ZIP code 93442. By the map's own method, the average of each year's coldest night over 1991-2020, Morro Bay's NOAA station is in zone 10a: the coldest night of a typical year reaches 33°F (17 complete years); the map interpolates between stations and terrain, so the station and the ZIP area can differ by half a zone.
Frost dates for every NOAA station in California · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00045866; 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 Morro Bay?
In a normal year in Morro Bay, 1 day a year reaches 90°F, 3 nights fall to 32°F or colder and 42 days bring measurable precipitation.
- Days at 90°F or more
- 1a normal year
- Days at 100°F or more
- fewer than 1a 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
- 42a normal year
The highest temperature in this station's record (since 1959) is 106°F, on October 4, 1987; the lowest is 22°F, on February 2, 2007.
The wettest calendar year on that record is 1978, with 27.71 in; the snowiest season is 2007–08, with 1.5 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00045866; records: ACIS (NOAA Regional Climate Centers), station USC00045866. Records use complete months only; a month missing more than three days is left out.
How sunny is Morro Bay?
Over a year 90% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Morro Bay, 5.5 kWh per square metre a day. June is the sunniest month (95%) and December the cloudiest (80%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 81% | 2.9 |
| February | 81% | 3.8 |
| March | 84% | 5.2 |
| April | 87% | 6.6 |
| May | 91% | 7.7 |
| June | 95% | 8.3 |
| July | 94% | 8.0 |
| August | 95% | 7.3 |
| September | 95% | 6.2 |
| October | 91% | 4.6 |
| November | 86% | 3.3 |
| December | 80% | 2.6 |
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 Morro Bay need?
A normal year in Morro Bay brings 2,194 heating degree days, 59% fewer than the median U.S. place (5,373), and 208 cooling degree days, 77% fewer than the median (908). No month reaches 300 heating degree days. For gardens and crops, NOAA counts 3,512 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 289 | 3 |
| February | 239 | 4 |
| March | 244 | 5 |
| April | 210 | 8 |
| May | 184 | 7 |
| June | 158 | 8 |
| July | 122 | 24 |
| August | 87 | 33 |
| September | 83 | 45 |
| October | 104 | 55 |
| November | 175 | 15 |
| December | 299 | 1 |
| Year (annual) | 2,194 | 208 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00045866. 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 Morro Bay's climate compare?
Morro Bay is warmer than 84 of the other 218 places with their own NOAA record in California, and wetter than 117. Across the 7,247 U.S. stations with normals, its annual mean of 59.5°F is warmer than 73%.
In the Köppen classification computed from these normals, Morro Bay 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 Morro Bay share this climate record?
3 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.
- Atascadero, CA29,743 people · 12 mi NE
- Los Osos, CA15,048 people · 4 mi S
- Cayucos, CA2,517 people · 6 mi NW
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 Morro Bay's climate
What is the coldest month in Morro Bay?
December, with a normal high of 65°F and a normal low of 46°F. The warmest is September (72°F by day, 56°F at night).
Does it snow in Morro Bay?
Rarely: NOAA's normal is 0.1 inch a year.
What is the rainiest month in Morro Bay?
January, with 3.64 in of precipitation in a normal year; the driest is August with 0.02 in.
What plant hardiness zone is Morro Bay in?
The USDA's 2023 map puts Morro Bay in zone 9b in ZIP code 93442. By the same method at Morro Bay's NOAA station, the coldest night of a typical year reaches 33°F (17 years, 1991-2020): zone 10a.
Nearby and next
- Morro Bay in OctoberThis month day by day, its records and recent years
- California climateThe statewide normals and every place in the state
- San Luis Obispo Poly, CA11 miles from this station, 60.5°F a year
- San Luis Obispo, CA14 miles from this station, 59.7°F a year
- Pismo Beach, CA17 miles from this station, 59.1°F a year
- Paso Robles, CA24 miles from this station, 60.0°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made