Santa Susana reaches 100° on about 14 days a year, more than 93% of U.S. towns
Midwinter brings lows of about 45°. Expect the heaviest rain or snow in February and the lightest in July. Winters are mild: January nights here are milder than in 94% of U.S. towns. Long walks are most pleasant from October to June, when afternoons reach 65–83°.
A year in Santa Susana at a glance
Each month’s typical high and low, and what it brings.
What stands out about Santa Susana’s climate
Compared with towns across the U.S., with Santa Susana’s place in California beside it.
What a year in Santa Susana feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 14 days a year reach 100°
And 76 days reach 90°. Frost and day counts come from NOAA’s station at Northridge Cal State, CA, 8 miles from the town’s center, 380 ft lower.
The 2023 USDA map puts Santa Susana’s center in zone 10a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 34°. Plant labels use the zone; frost dates tell you when to plant.
90° days by month
Average days at 90° or more
About 18 inches of rain a year
February is the wettest month and July the driest. Rain falls on about 31 days a year. Snow is rare: about 0.0" in a normal year at Piru 2 Ese, CA, so most winters see none.
Rain + melted snow by month
Inches of water
Heating and cooling a home in Santa Susana
43% of the work is heating, so air conditioning is the bigger bill. Months averaging under 55°: 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 Northridge Cal State, CA.
Living with Santa Susana’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
Zone 10a. Frost comes about 1 winter in 5, so the growing year is set by heat, not cold: 14 days at 100° make midsummer the hard season for gardens.
Months with highs of 62–84° and lows of 40° or more: January, February, March, April, May, June, October, November and December. 2.9 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Santa Susana from natural hazards, river flooding is the largest share (54%). Normals are averages; the hazards page covers the extremes.
Natural hazards →Santa Susana and its neighbors
Simi Valley has the coldest January nights next door (44°, 1° colder). Differences under a degree are within what the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Santa Susana’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 |
|---|---|---|---|---|
| Santa Susana, CA | 45° | 90° | 18" | 0.0" |
| Port Isabel, TX | 52° | 92° | 26" | 0.2" |
| Sierra Vista Southeast, AZ | 32° | 91° | 15" | 0.7" |
| Ashland, OR | 31° | 91° | 19" | 0.5" |
| College Place, WA | 30° | 91° | 15" | 7.2" |
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value. Snow and frost-free days come from the nearest weather station, so neighbors often share them.
Warmer than it used to be
The last 30 years in Santa Susana averaged 2.5° warmer than the 1900s. The biggest change is in January (+3.3°).
A bigger shift than in all but 93 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 Santa Susana compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Santa Susana’s place among California’s.
Santa Susana weather by month
Highs, lows and precipitation from NOAA’s grid at Santa Susana’s center; snow, wet days and snow on the ground from Piru 2 Ese, CA. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 65° | 45° | 4.0" | 0.0" | 6 | 0 | 51° – 62° |
| February | 65° | 44° | 4.6" | 0.0" | 6 | 0 | 48° – 63° |
| March | 69° | 46° | 2.9" | 0.0" | 5 | 0 | 50° – 65° |
| April | 73° | 48° | 0.9" | 0.0" | 2 | 0 | 55° – 64° |
| May | 77° | 52° | 0.4" | 0.0" | 1 | 0 | 57° – 72° |
| June | 83° | 57° | 0.1" | 0.0" | 0 | 0 | 65° – 75° |
| July | 90° | 62° | 0.0" | 0.0" | 0 | 0 | 72° – 81° |
| August | 92° | 63° | 0.0" | 0.0" | 0 | 0 | 74° – 81° |
| September | 88° | 61° | 0.1" | 0.0" | 1 | 0 | 70° – 79° |
| October | 80° | 55° | 0.7" | 0.0" | 2 | 0 | 63° – 74° |
| November | 72° | 49° | 1.2" | 0.0" | 3 | 0 | 54° – 65° |
| December | 65° | 44° | 3.1" | 0.0" | 5 | 0 | 50° – 61° |
| Year | 77° | 52° | 17.9" | 0.0" | 31 | 0 |
How much a month can swing
A normal is an average. March swings the most: from 1991 to 2020 its average ranged from 50° to 65°. August is the most reliable, staying within 7°.
Where Santa Susana’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 Santa Susana’s center.
- Snow: Piru 2 Ese, CA.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Northridge Cal State, CA, 8 miles from the town’s center, 380 ft lower; 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 Santa Susana’s climate
What is the weather like in Santa Susana?
A typical July afternoon reaches 90°, a January night drops to 45°, and snow is almost unheard of. Milder January nights than 94% of U.S. towns; hotter July afternoons than 77% of U.S. towns.
How cold does it get in Santa Susana in winter?
December nights average 44°. A night at 32° or below comes in only some winters (0.6 a year on average). In the coldest December of the last 30 years the month averaged 50°.
How much snow does Santa Susana get?
About 0.0 inches in a normal winter at Piru 2 Ese, CA, so most winters see none.
How hot does it get in Santa Susana?
July, with a typical high of 90° and a low of 62°. About 76 days a year reach 90° and 14 reach 100° (Northridge Cal State, CA).
When is the first and last frost in Santa Susana?
Most years have no frost at all: a 32° night comes in about 18% of winters at Northridge Cal State, CA, usually in December or January.
What growing zone is Santa Susana in?
Zone 10a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 34°.
What is the best time of year to visit Santa Susana?
By one simple rule (highs of 62–84° and lows of 40° or more), January, February, March, April, May, June, October, November and December. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Santa Susana getting warmer?
Yes: 1991–2020 averaged 2.5° warmer than 1901–2000 on NOAA’s grid. A bigger shift than all but 93 U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Santa Susana.
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.