Photo: Jeffrey Beall · CC BY 4.0Precipitation in Grenville trails that of 92% of U.S. towns: 17 inches a year
Expect July afternoons of about 87°. In January, nights here are colder than in 70% of U.S. towns. Decade by decade the climate has edged up, 1.1° above 1901–2000. Tender plants can go out after about May 5; in half of years the first frost comes by October 9.
A year in Grenville at a glance
Each month’s typical high and low, and what it brings.
What stands out about Grenville’s climate
Compared with towns across the U.S., with Grenville’s place in New Mexico beside it.
What a year in Grenville feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 156 frost-free days a year
In half of years the last 32° night comes by May 5 and the first by October 9. Frost and day counts come from NOAA’s station at Grenville, NM, 0.4 miles from the town’s center, at about the same height.
The 2023 USDA map puts Grenville’s center in zone 6b: the coldest night of a typical winter, averaged over 1991–2020, reaches about −5°. 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 18 inches of snow a winter
Snow, measured at Grenville, NM, falls mostly in December. Precipitation (rain plus melted snow) adds up to 17 inches a year; July is the wettest month and February the driest. Rain or snow falls on about 56 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Grenville
90% of the work is heating, so the furnace matters far more than the air conditioner. 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 Grenville, NM.
Living with Grenville’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
156 frost-free days in zone 6b. The last frost comes by May 5 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 9.
Months with highs of 62–84° and lows of 40° or more: May, June, August and September.
Parks & trails →Of the yearly building losses FEMA expects in Grenville from natural hazards, drought is the largest share (37%); heat waves, cold waves, winter storms and ice storms together are 7%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Grenville and similar climates
TownRatings has no climate map of the towns around Grenville yet.
Climates most like Grenville’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 |
|---|---|---|---|---|
| Grenville, NM | 18° | 87° | 17" | 18" |
| Show Low, AZ | 19° | 86° | 15" | 19" |
| Hamilton, MT | 20° | 86° | 13" | 17" |
| Blackfoot, ID | 16° | 88° | 11" | 15" |
| Security-Widefield, CO | 18° | 87° | 16" | 33" |
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 Grenville averaged 1.1° warmer than the 1900s. The biggest change is in March (+2.7°).
A smaller shift than in 68% 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 Grenville compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Grenville’s place among New Mexico’s.
Grenville weather by month
Highs, lows and precipitation from NOAA’s grid at Grenville’s center; snow, wet days and snow on the ground from Grenville, NM. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 47° | 18° | 0.4" | 3.2" | 2 | 1 | 24° – 37° |
| February | 49° | 20° | 0.4" | 3.3" | 2 | 2 | 25° – 42° |
| March | 57° | 26° | 0.8" | 2.1" | 3 | 1 | 38° – 47° |
| April | 64° | 33° | 1.1" | 1.3" | 5 | 0 | 42° – 54° |
| May | 73° | 42° | 1.7" | 0.0" | 6 | 0 | 53° – 64° |
| June | 83° | 52° | 2.0" | 0.0" | 7 | 0 | 62° – 72° |
| July | 87° | 57° | 3.3" | 0.0" | 9 | 0 | 69° – 76° |
| August | 84° | 56° | 3.2" | 0.0" | 9 | 0 | 66° – 74° |
| September | 77° | 48° | 1.7" | 0.0" | 5 | 0 | 56° – 68° |
| October | 67° | 36° | 0.9" | 0.7" | 3 | 0 | 46° – 57° |
| November | 55° | 26° | 0.5" | 2.2" | 3 | 1 | 33° – 48° |
| December | 46° | 18° | 0.5" | 5.1" | 2 | 2 | 25° – 37° |
| Year | 66° | 36° | 16.5" | 17.9" | 56 | 7 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 25° to 42°. July is the most reliable, staying within 8°.
Where Grenville’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 Grenville’s center.
- Snow: Grenville, NM (NOAA station in town).
- Frost, freezing nights, 90° and 100° days, heating and cooling: Grenville, NM, 0.4 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 Grenville’s climate
What is the weather like in Grenville?
A typical July afternoon reaches 87°, a January night drops to 18°, and about 18 inches of snow falls in a normal winter. Colder January nights than 70% of U.S. towns; hotter July afternoons than 59% of U.S. towns.
How cold does it get in Grenville in winter?
January nights average 18°. About 153 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 Grenville get?
About 18 inches in a normal winter at Grenville, NM, most of it in December, with snow on the ground about 7 days a year.
How hot does it get in Grenville?
July, with a typical high of 87° and a low of 57°. About 30 days a year reach 90° (Grenville, NM).
When is the first and last frost in Grenville?
In half of years the last spring frost (32°) comes by May 5 and the first fall frost by October 9, about 156 frost-free days, at Grenville, NM.
What growing zone is Grenville in?
Zone 6b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −5°.
What is the best time of year to visit Grenville?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June, August and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Grenville getting warmer?
Yes: 1991–2020 averaged 1.1° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 68% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Grenville.
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.