Sullivan is among the driest of U.S. towns: 8 inches of precipitation a year
High summer brings afternoon highs near 93°. In July, afternoons here are warmer than in 90% of U.S. towns. Since 1901–2000, the year has warmed by 1.7°, most of all in January. The heating season runs November to March: each of those months averages under 50°.
A year in Sullivan at a glance
Each month’s typical high and low, and what it brings.
What stands out about Sullivan’s climate
Compared with towns across the U.S., with Sullivan’s place in New Mexico beside it.
What a year in Sullivan feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 147 frost-free days a year
In half of years the last 32° night comes by May 12 and the first by October 6. Day counts come from NOAA’s station at Bloomfield 3 Se, NM, 4 miles from the town’s center, 280 ft higher; frost dates and degree days from Aztec Ruins Nm, NM, 11 miles away.
The 2023 USDA map puts Sullivan’s center in zone 7a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 1°. 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 11 inches of snow a winter
Snow, measured at Aztec Ruins Nm, NM, falls mostly in January. Precipitation (rain plus melted snow) adds up to 8 inches a year; August is the wettest month and June the driest. Rain or snow falls on about 57 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Sullivan
85% of the work is heating. Months averaging under 55° run from October through April.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Aztec Ruins Nm, NM.
Living with Sullivan’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
147 frost-free days in zone 7a. The last frost comes by May 12 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Oct 6.
Months with highs of 62–84° and lows of 40° or more: May and September. 12 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Sullivan from natural hazards, river flooding is the largest share (93%); heat waves, cold waves, winter storms and ice storms together are 3%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Sullivan and its neighbors
Every town next door is within a degree of Sullivan in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Sullivan’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 |
|---|---|---|---|---|
| Sullivan, NM | 17° | 93° | 8" | 11" |
| Fruitvale, CO | 19° | 94° | 10" | 13" |
| Price, UT | 14° | 92° | 9" | 8.7" |
| Winnemucca, NV | 21° | 93° | 8" | 22" |
| Snowflake, AZ | 20° | 90° | 10" | 13" |
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 Sullivan averaged 1.7° warmer than the 1900s. The biggest change is in January (+2.6°).
A bigger shift than in 73% 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 Sullivan compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Sullivan’s place among New Mexico’s.
Sullivan weather by month
Highs, lows and precipitation from NOAA’s grid at Sullivan’s center; snow, wet days and snow on the ground from Aztec Ruins Nm, NM. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 43° | 17° | 0.6" | 4.5" | 6 | 3 | 24° – 36° |
| February | 50° | 23° | 0.5" | 2.3" | 5 | 2 | 32° – 42° |
| March | 60° | 28° | 0.6" | 0.5" | 4 | 0 | 40° – 50° |
| April | 68° | 34° | 0.6" | 0.2" | 4 | 0 | 47° – 55° |
| May | 78° | 43° | 0.6" | 0.0" | 4 | 0 | 55° – 64° |
| June | 89° | 52° | 0.3" | 0.0" | 2 | 0 | 66° – 76° |
| July | 93° | 60° | 0.9" | 0.0" | 5 | 0 | 72° – 79° |
| August | 90° | 58° | 1.1" | 0.0" | 7 | 0 | 70° – 79° |
| September | 82° | 49° | 1.1" | 0.0" | 6 | 0 | 60° – 69° |
| October | 70° | 37° | 0.8" | 0.3" | 5 | 0 | 49° – 58° |
| November | 55° | 26° | 0.6" | 0.9" | 4 | 1 | 34° – 47° |
| December | 43° | 18° | 0.6" | 2.2" | 5 | 3 | 24° – 36° |
| Year | 68° | 37° | 8.3" | 10.9" | 57 | 9 |
How much a month can swing
A normal is an average. November swings the most: from 1991 to 2020 its average ranged from 34° to 47°. July is the most reliable, staying within 7°.
Where Sullivan’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 Sullivan’s center.
- Snow: Aztec Ruins Nm, NM.
- Frost dates, heating and cooling: Aztec Ruins Nm, NM, 11 miles away.
- Freezing nights, 90° and 100° days: Bloomfield 3 Se, NM, 4 miles from the town’s center, 280 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 Sullivan’s climate
What is the weather like in Sullivan?
A typical July afternoon reaches 93°, a January night drops to 17°, and about 11 inches of snow falls in a normal winter. Colder January nights than 74% of U.S. towns; hotter July afternoons than 90% of U.S. towns.
How cold does it get in Sullivan in winter?
January nights average 17°. About 135 nights a year reach 32° or below. In the coldest January of the last 30 years the month averaged 24°.
How much snow does Sullivan get?
About 11 inches in a normal winter at Aztec Ruins Nm, NM, most of it in January, with snow on the ground about 9 days a year.
How hot does it get in Sullivan?
July, with a typical high of 93° and a low of 60°. About 60 days a year reach 90° (Aztec Ruins Nm, NM).
When is the first and last frost in Sullivan?
In half of years the last spring frost (32°) comes by May 12 and the first fall frost by October 6, about 147 frost-free days, at Aztec Ruins Nm, NM.
What growing zone is Sullivan in?
Zone 7a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 1°.
What is the best time of year to visit Sullivan?
By one simple rule (highs of 62–84° and lows of 40° or more), May and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Sullivan getting warmer?
Yes: 1991–2020 averaged 1.7° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 73% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Sullivan.
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.