Powerhouse, The · Photo: mountmonty · CC BY-SA 3.0California Polytechnic State University sits near the bottom of U.S. towns for July heat
January mornings start at about 42°. Winters are mild: January nights here are milder than in 90% of U.S. towns. Compared with 1901–2000, the average now sits 2.0° higher. Long walks are most pleasant from January to December, when afternoons reach 63–80°.
A year in California Polytechnic State University at a glance
Each month’s typical high and low, and what it brings.
What stands out about California Polytechnic State University’s climate
Compared with towns across the U.S., with California Polytechnic State University’s place in California State beside it.
What a year in California Polytechnic State University feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
A freeze most winters
Frost and day counts come from NOAA’s station at San Luis Obispo Poly, CA, 0.3 miles from the town’s center, at about the same height.
The 2023 USDA map puts California Polytechnic State University’s center in zone 9b: the coldest night of a typical winter, averaged over 1991–2020, reaches about 30°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
About 21 inches of rain a year
January is the wettest month and July the driest. Rain falls on about 52 days a year. Snow is rare: about 0.0" in a normal year at Santa Margarita Boost, CA, so most winters see none.
Rain + melted snow by month
Inches of water
Heating and cooling a home in California Polytechnic State University
83% of the work is heating. Months averaging under 55° run from December through February.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at San Luis Obispo Poly, CA.
Living with California Polytechnic State University’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
Zone 9b. Frost comes about 7 winters in 10, so tender plants can often stay out through winter.
Months with highs of 62–84° and lows of 40° or more: January, February, March, April, May, June, July, August, September, October, November and December. 11 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in California Polytechnic State University from natural hazards, river flooding is the largest share (62%); heat waves, cold waves, winter storms and ice storms together are 1%. Normals are averages; the hazards page covers the extremes.
Natural hazards →California Polytechnic State University and similar climates
TownRatings has no climate map of the towns around California Polytechnic State University yet.
Climates most like California Polytechnic State University’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| California Polytechnic State University, CA | 42° | 78° | 21" | 0.0" |
| Makawao, HI | 53° | 75° | 23" | 0.0" |
| Poulsbo, WA | 35° | 75° | 33" | 3.0" |
| Tualatin, OR | 36° | 81° | 40" | 1.0" |
| Hayden, ID | 25° | 83° | 26" | 27" |
Temperatures and precipitation come from NOAA’s 5 km grid; snow and day counts from the stations named on this page.
Warmer than it used to be
The last 30 years in California Polytechnic State University averaged 2.0° warmer than the 1900s. The biggest change is in January (+2.8°).
A bigger shift than in 91% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How California Polytechnic State University compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with California Polytechnic State University’s place among California State’s.
California Polytechnic State University weather by month
Highs, lows and precipitation from NOAA’s grid at California Polytechnic State University’s center; snow, wet days and snow on the ground from Santa Margarita Boost, CA. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 64° | 42° | 4.7" | 0.0" | 9 | 0 | 49° – 57° |
| February | 64° | 42° | 4.5" | 0.0" | 10 | 0 | 49° – 59° |
| March | 66° | 44° | 3.7" | 0.0" | 9 | 0 | 48° – 61° |
| April | 69° | 45° | 1.2" | 0.0" | 5 | 0 | 52° – 61° |
| May | 72° | 48° | 0.5" | 0.0" | 2 | 0 | 55° – 65° |
| June | 76° | 51° | 0.1" | 0.0" | 1 | 0 | 58° – 67° |
| July | 78° | 54° | 0.0" | 0.0" | 0 | 0 | 63° – 70° |
| August | 79° | 54° | 0.0" | 0.0" | 0 | 0 | 64° – 70° |
| September | 80° | 52° | 0.1" | 0.0" | 1 | 0 | 62° – 71° |
| October | 77° | 49° | 0.8" | 0.0" | 3 | 0 | 58° – 69° |
| November | 70° | 44° | 1.7" | 0.0" | 5 | 0 | 50° – 61° |
| December | 63° | 41° | 3.6" | 0.0" | 8 | 0 | 49° – 57° |
| Year | 71° | 47° | 20.8" | 0.0" | 52 | 0 |
How much a month can swing
A normal is an average. March swings the most: from 1991 to 2020 its average ranged from 48° to 61°. August is the most reliable, staying within 6°.
Where California Polytechnic State University’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at California Polytechnic State University’s center.
- Snow: Santa Margarita Boost, CA.
- Frost, freezing nights, 90° and 100° days, heating and cooling: San Luis Obispo Poly, CA, 0.3 miles from the town’s center, at about the same height; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about California Polytechnic State University’s climate
What is the weather like in California Polytechnic State University?
A typical July afternoon reaches 78°, a January night drops to 42°, and snow is almost unheard of. Milder January nights than 90% of U.S. towns; cooler July afternoons than 96% of U.S. towns.
How cold does it get in California Polytechnic State University in winter?
December nights average 41°. About 3 nights a year reach 32° or below. In the coldest December of the last 30 years the month averaged 49°.
How much snow does California Polytechnic State University get?
About 0.0 inches in a normal winter at Santa Margarita Boost, CA, so most winters see none.
How hot does it get in California Polytechnic State University?
July, with a typical high of 78° and a low of 54°. About 19 days a year reach 90° and 2 reach 100° (San Luis Obispo Poly, CA).
When is the first and last frost in California Polytechnic State University?
There is no reliable frost date: a 32° night comes in about 68% of winters at San Luis Obispo Poly, CA, so most years bring a freeze but some pass without one.
What growing zone is California Polytechnic State University in?
Zone 9b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 30°.
What is the best time of year to visit California Polytechnic State University?
By one simple rule (highs of 62–84° and lows of 40° or more), January, February, March, April, May, June, July, August, September, October, November and December. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is California Polytechnic State University getting warmer?
Yes: 1991–2020 averaged 2.0° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 91% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in California Polytechnic State University.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.