Capilla de Viejo San Acacio · Photo: Jeffrey Beall · CC BY-SA 3.0Few U.S. towns have colder winter nights than San Acacio
Midsummer highs settle at about 82°. From frosty January to warm July, readings climb 74°. By precipitation alone, it ranks drier than 96% of U.S. towns. Seedlings are safe outdoors from about May 31, with the first autumn frost due around September 23.
A year in San Acacio at a glance
Each month’s typical high and low, and what it brings.
What stands out about San Acacio’s climate
Compared with towns across the U.S., with San Acacio’s place in Colorado beside it.
What a year in San Acacio feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 115 frost-free days a year
In half of years the last 32° night comes by May 31 and the first by September 23. Frost and day counts come from NOAA’s station at San Luis 1 S, CO, 8 miles from the town’s center, 220 ft higher.
The 2023 USDA map puts San Acacio’s center in zone 5a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −17°. 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 30 inches of snow a winter
Snow, measured at Manassa, CO, falls mostly in March and December. Precipitation (rain plus melted snow) adds up to 12 inches a year; July is the wettest month and February the driest. Rain or snow falls on about 53 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in San Acacio
99% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October through May.
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 1 S, CO.
Living with San Acacio’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
115 frost-free days in zone 5a. The last frost comes by May 31 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Sep 23.
Months with highs of 62–84° and lows of 40° or more: June, July, August and September. 1.8 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in San Acacio from natural hazards, river flooding is the largest share (59%); heat waves, cold waves, winter storms and ice storms together are 9%. Normals are averages; the hazards page covers the extremes.
Natural hazards →San Acacio and similar climates
TownRatings has no climate map of the towns around San Acacio yet.
Climates most like San Acacio’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 |
|---|---|---|---|---|
| San Acacio, CO | 8° | 82° | 12" | 30" |
| Dickinson, ND | 5° | 83° | 16" | 35" |
| Havre, MT | 6° | 85° | 13" | 41" |
| Cody, WY | 14° | 85° | 11" | 45" |
| Aberdeen, SD | 3° | 84° | 22" | 43" |
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 San Acacio averaged 1.6° warmer than the 1900s. The biggest change is in March (+3.2°).
A bigger shift than in 65% 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 San Acacio compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with San Acacio’s place among Colorado’s.
San Acacio weather by month
Highs, lows and precipitation from NOAA’s grid at San Acacio’s center; snow, wet days and snow on the ground from Manassa, CO. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | 30-yr range |
|---|---|---|---|---|---|---|
| January | 38° | 8° | 0.6" | 4.6" | 2 | 15° – 30° |
| February | 42° | 13° | 0.6" | 3.0" | 3 | 21° – 35° |
| March | 51° | 21° | 0.9" | 5.5" | 3 | 33° – 42° |
| April | 59° | 27° | 1.0" | 3.6" | 3 | 39° – 48° |
| May | 69° | 35° | 1.1" | 0.4" | 4 | 47° – 57° |
| June | 79° | 44° | 0.7" | 0.0" | 4 | 57° – 66° |
| July | 82° | 49° | 1.9" | 0.0" | 9 | 63° – 69° |
| August | 79° | 47° | 1.8" | 0.0" | 9 | 61° – 67° |
| September | 73° | 40° | 1.3" | 0.0" | 7 | 51° – 60° |
| October | 63° | 29° | 1.0" | 2.5" | 4 | 42° – 51° |
| November | 49° | 18° | 0.7" | 4.5" | 3 | 26° – 41° |
| December | 38° | 9° | 0.6" | 5.6" | 3 | 18° – 30° |
| Year | 60° | 28° | 12.2" | 29.7" | 53 |
How much a month can swing
A normal is an average. November swings the most: from 1991 to 2020 its average ranged from 26° to 41°. August is the most reliable, staying within 6°.
Where San Acacio’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 San Acacio’s center.
- Snow: Manassa, CO.
- Frost, freezing nights, 90° and 100° days, heating and cooling: San Luis 1 S, CO, 8 miles from the town’s center, 220 ft higher; 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 San Acacio’s climate
What is the weather like in San Acacio?
A typical July afternoon reaches 82°, a January night drops to 8°, and about 30 inches of snow falls in a normal winter. Colder January nights than 96% of U.S. towns; cooler July afternoons than 80% of U.S. towns.
How cold does it get in San Acacio in winter?
January nights average 8°. About 211 nights a year reach 32° or below and 23 reach 0° or below. In the coldest January of the last 30 years the month averaged 15°.
How much snow does San Acacio get?
About 30 inches in a normal winter at Manassa, CO, most of it in March and December.
How hot does it get in San Acacio?
July, with a typical high of 82° and a low of 49°. About 2 days a year reach 90° (San Luis 1 S, CO).
When is the first and last frost in San Acacio?
In half of years the last spring frost (32°) comes by May 31 and the first fall frost by September 23, about 115 frost-free days, at San Luis 1 S, CO.
What growing zone is San Acacio in?
Zone 5a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −17°.
What is the best time of year to visit San Acacio?
By one simple rule (highs of 62–84° and lows of 40° or more), June, July, August and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is San Acacio getting warmer?
Yes: 1991–2020 averaged 1.6° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 65% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in San Acacio.
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.