Few U.S. towns get less rain and snow than South River: 9 inches a year
The depth of winter brings overnight lows near 18°. Its July heat outdoes that of 86% of U.S. towns. Compared with 1901–2000, the average now sits 1.7° higher. Picnics, hikes and garden evenings suit May and September, with highs of 77–81°.
A year in South River at a glance
Each month’s typical high and low, and what it brings.
What stands out about South River’s climate
Compared with towns across the U.S., with South River’s place in New Mexico beside it.
What a year in South River 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. Frost and day counts come from NOAA’s station at Aztec Ruins Nm, NM, 5 miles from the town’s center, at about the same height.
The 2023 USDA map puts South River’s center in zone 7a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 0°. 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 9 inches a year; September 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 South River
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 South River’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. 11 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in South River from natural hazards, river flooding is the largest share (79%); heat waves, cold waves, winter storms and ice storms together are 13%. Normals are averages; the hazards page covers the extremes.
Natural hazards →South River and its neighbors
Every town next door is within a degree of South River in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like South River’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 |
|---|---|---|---|---|
| South River, NM | 18° | 92° | 9" | 11" |
| Pueblo West, CO | 19° | 92° | 12" | 15" |
| Snowflake, AZ | 20° | 90° | 10" | 13" |
| Price, UT | 14° | 92° | 9" | 8.7" |
| Johnson Lane, NV | 22° | 91° | 10" | 14" |
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 South River 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 South River compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with South River’s place among New Mexico’s.
South River weather by month
Highs, lows and precipitation from NOAA’s grid at South River’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 | 42° | 18° | 0.8" | 4.5" | 6 | 3 | 24° – 37° |
| February | 49° | 23° | 0.7" | 2.3" | 5 | 2 | 32° – 42° |
| March | 59° | 29° | 0.7" | 0.5" | 4 | 0 | 40° – 50° |
| April | 67° | 35° | 0.6" | 0.2" | 4 | 0 | 47° – 55° |
| May | 77° | 43° | 0.6" | 0.0" | 4 | 0 | 55° – 64° |
| June | 88° | 52° | 0.3" | 0.0" | 2 | 0 | 65° – 76° |
| July | 92° | 60° | 0.8" | 0.0" | 5 | 0 | 72° – 79° |
| August | 89° | 59° | 1.1" | 0.0" | 7 | 0 | 71° – 78° |
| September | 81° | 50° | 1.1" | 0.0" | 6 | 0 | 60° – 69° |
| October | 69° | 38° | 0.9" | 0.3" | 5 | 0 | 49° – 58° |
| November | 54° | 26° | 0.7" | 0.9" | 4 | 1 | 34° – 47° |
| December | 42° | 19° | 0.7" | 2.2" | 5 | 3 | 25° – 37° |
| Year | 67° | 38° | 9.0" | 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°. August is the most reliable, staying within 7°.
Where South River’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 South River’s center.
- Snow: Aztec Ruins Nm, NM.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Aztec Ruins Nm, NM, 5 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 South River’s climate
What is the weather like in South River?
A typical July afternoon reaches 92°, a January night drops to 18°, and about 11 inches of snow falls in a normal winter. Colder January nights than 68% of U.S. towns; hotter July afternoons than 86% of U.S. towns.
How cold does it get in South River in winter?
January nights average 18°. About 158 nights a year reach 32° or below and 2 reach 0° or below. In the coldest January of the last 30 years the month averaged 24°.
How much snow does South River 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 South River?
July, with a typical high of 92° and a low of 60°. About 61 days a year reach 90° and 2 reach 100° (Aztec Ruins Nm, NM).
When is the first and last frost in South River?
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 South River in?
Zone 7a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 0°.
What is the best time of year to visit South River?
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 South River 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 South River.
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.