Photo: w:User:matthewstringer · CC BY-SA 3.0Duarte’s winters are milder and less snowy than most of the U.S.
A typical July afternoon reaches 90°, a January night drops to 44°, and snow is almost unheard of.
A year in Duarte at a glance
Each month’s typical high and low, and what it brings.
What stands out about Duarte’s climate
Compared with towns across the U.S., with Duarte’s place in California beside it.
What a year in Duarte feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
Frost is rare
Frost and day counts come from Pasadena, CA, 11 miles away.
The 2023 USDA map puts Duarte’s center in zone 10b: the coldest night of a typical winter, averaged over 1991–2020, reaches about 36°. Plant labels use the zone; frost dates tell you when to plant.
90° days by month
Average days at 90° or more
About 19 inches of rain a year
February is the wettest month and August the driest. Rain falls on about 46 days a year. Snow is rare: about 0.0" in a normal year at San Gabriel Canyon Ph, CA, so most winters see none.
Rain + melted snow by month
Inches of water
Heating and cooling a home in Duarte
44% of the work is heating, so air conditioning is the bigger bill. No month averages under 55°.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Pasadena, CA.
Living with Duarte’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
Zone 10b. Frost comes about 1 winter in 8, 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, October, November and December. 6.1 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Duarte from natural hazards, earthquakes are the largest share (52%); heat waves, cold waves, winter storms and ice storms together are 1%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Duarte and its neighbors
Azusa has the coldest January nights next door (43°, 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 Duarte’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 |
|---|---|---|---|---|
| Duarte, CA | 44° | 90° | 19" | 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 Duarte averaged 2.6° warmer than the 1900s. The biggest change is in January (+3.5°).
A bigger shift than in all but 39 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 Duarte compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Duarte’s place among California’s.
Duarte weather by month
Highs, lows and precipitation from NOAA’s grid at Duarte’s center; snow, wet days and snow on the ground from San Gabriel Canyon Ph, CA. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 68° | 44° | 4.4" | 0.0" | 7 | 0 | 52° – 63° |
| February | 69° | 45° | 4.9" | 0.0" | 8 | 0 | 50° – 67° |
| March | 72° | 47° | 2.8" | 0.0" | 7 | 0 | 53° – 67° |
| April | 75° | 50° | 1.1" | 0.0" | 4 | 0 | 57° – 67° |
| May | 78° | 54° | 0.4" | 0.0" | 4 | 0 | 61° – 73° |
| June | 84° | 59° | 0.1" | 0.0" | 2 | 0 | 67° – 76° |
| July | 90° | 62° | 0.0" | 0.0" | 1 | 0 | 73° – 81° |
| August | 92° | 63° | 0.0" | 0.0" | 0 | 0 | 74° – 81° |
| September | 89° | 60° | 0.2" | 0.0" | 1 | 0 | 70° – 79° |
| October | 82° | 55° | 0.8" | 0.0" | 3 | 0 | 64° – 73° |
| November | 74° | 48° | 1.2" | 0.0" | 4 | 0 | 53° – 65° |
| December | 67° | 43° | 3.0" | 0.0" | 6 | 0 | 51° – 61° |
| Year | 78° | 52° | 18.9" | 0.0" | 46 | 0 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 50° to 67°. August is the most reliable, staying within 7°.
Where Duarte’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 Duarte’s center.
- Snow: San Gabriel Canyon Ph, CA.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Pasadena, CA, 11 miles from the town’s center, 640 ft lower; no station nearby passes every check; this is the nearest one in the same valley, flagged above.
- 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 Duarte’s climate
What is the weather like in Duarte?
A typical July afternoon reaches 90°, a January night drops to 44°, and snow is almost unheard of. Milder January nights than 93% of U.S. towns; hotter July afternoons than 77% of U.S. towns.
How cold does it get in Duarte in winter?
December nights average 43°. A night at 32° or below comes in only some winters (0.1 a year on average). In the coldest December of the last 30 years the month averaged 51°.
How much snow does Duarte get?
About 0.0 inches in a normal winter at San Gabriel Canyon Ph, CA, so most winters see none.
How hot does it get in Duarte?
July, with a typical high of 90° and a low of 62°. About 74 days a year reach 90° and 10 reach 100° (Pasadena, CA).
When is the first and last frost in Duarte?
Most years have no frost at all: a 32° night comes in about 13% of winters at Pasadena, CA, usually in December or January.
What growing zone is Duarte in?
Zone 10b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 36°.
What is the best time of year to visit Duarte?
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 Duarte getting warmer?
Yes: 1991–2020 averaged 2.6° warmer than 1901–2000 on NOAA’s grid. A bigger shift than all but 39 U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Duarte.
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.