Photo: Darren Green · CC BY-SA 3.0A middle-of-the-road climate: Griggsville is close to most U.S. towns on every count
In July the day’s top temperature is typically 87°. Precipitation is light here, less than falls on 65% of U.S. towns. February has warmed most since 1901–2000, part of a 0.7° rise. Garden planting can start around April 18; autumn frost returns near October 15.
A year in Griggsville at a glance
Each month’s typical high and low, and what it brings.
What stands out about Griggsville’s climate
Compared with towns across the U.S., with Griggsville’s place in Illinois beside it.
What a year in Griggsville feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 179 frost-free days a year
In half of years the last 32° night comes by April 18 and the first by October 15. Frost and day counts come from NOAA’s station at Perry 6 Nw, IL, 9 miles from the town’s center, at about the same height.
The 2023 USDA map puts Griggsville’s center in zone 6a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −7°. 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 21 inches of snow a winter
Snow, measured at Perry 6 Nw, IL, is heaviest from January through February, about 6 inches a month. Precipitation (rain plus melted snow) adds up to 39 inches a year; June is the wettest month and February the driest. Rain or snow falls on about 113 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Griggsville
82% of the work is heating. Months averaging under 55° run from November 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 Perry 6 Nw, IL.
Living with Griggsville’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
179 frost-free days in zone 6a. The last frost comes by Apr 18 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 15.
Months with highs of 62–84° and lows of 40° or more: April, May, June, September and October.
Parks & trails →Of the yearly building losses FEMA expects in Griggsville from natural hazards, river flooding is the largest share (22%); heat waves, cold waves, winter storms and ice storms together are 34%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Griggsville and similar climates
TownRatings has no climate map of the towns around Griggsville yet.
Climates most like Griggsville’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 |
|---|---|---|---|---|
| Griggsville, IL | 19° | 87° | 39" | 21" |
| Savannah, MO | 18° | 87° | 37" | 21" |
| Huntingdon, PA | 21° | 85° | 40" | 26" |
| Strasburg, VA | 23° | 87° | 39" | 21" |
| Martinsburg, WV | 23° | 87° | 40" | 23" |
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 Griggsville averaged 0.7° warmer than the 1900s. The biggest change is in February (+1.8°).
A smaller shift than in 93% 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 Griggsville compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Griggsville’s place among Illinois’.
Griggsville weather by month
Highs, lows and precipitation from NOAA’s grid at Griggsville’s center; snow, wet days and snow on the ground from Perry 6 Nw, IL. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 36° | 19° | 2.0" | 6.1" | 9 | 12 | 21° – 39° |
| February | 41° | 23° | 1.9" | 6.0" | 8 | 8 | 20° – 43° |
| March | 52° | 32° | 2.7" | 2.4" | 10 | 3 | 34° – 56° |
| April | 65° | 42° | 4.0" | 0.4" | 12 | 0 | 46° – 60° |
| May | 75° | 53° | 4.7" | 0.0" | 13 | 0 | 58° – 73° |
| June | 83° | 62° | 4.7" | 0.0" | 11 | 0 | 69° – 78° |
| July | 87° | 66° | 4.0" | 0.0" | 9 | 0 | 71° – 82° |
| August | 85° | 63° | 3.4" | 0.0" | 9 | 0 | 69° – 80° |
| September | 79° | 55° | 3.5" | 0.0" | 8 | 0 | 62° – 73° |
| October | 67° | 44° | 3.1" | 0.0" | 9 | 0 | 50° – 61° |
| November | 53° | 34° | 2.7" | 0.9" | 8 | 1 | 35° – 51° |
| December | 40° | 24° | 2.1" | 5.1" | 9 | 8 | 18° – 41° |
| Year | 63° | 43° | 38.7" | 20.9" | 113 | 31 |
How much a month can swing
A normal is an average. December swings the most: from 1991 to 2020 its average ranged from 18° to 41°. June is the most reliable, staying within 9°.
Where Griggsville’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 Griggsville’s center.
- Snow: Perry 6 Nw, IL.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Perry 6 Nw, IL, 9 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 Griggsville’s climate
What is the weather like in Griggsville?
A typical July afternoon reaches 87°, a January night drops to 19°, and about 21 inches of snow falls in a normal winter. Colder January nights than 63% of U.S. towns; hotter July afternoons than 59% of U.S. towns.
How cold does it get in Griggsville in winter?
January nights average 19°. About 126 nights a year reach 32° or below and 7 reach 0° or below. In the coldest January of the last 30 years the month averaged 21°.
How much snow does Griggsville get?
About 21 inches in a normal winter at Perry 6 Nw, IL, heaviest from January through February, about 6 inches a month, with snow on the ground about 31 days a year.
How hot does it get in Griggsville?
July, with a typical high of 87° and a low of 66°. About 31 days a year reach 90° and 1 reach 100° (Perry 6 Nw, IL).
When is the first and last frost in Griggsville?
In half of years the last spring frost (32°) comes by April 18 and the first fall frost by October 15, about 179 frost-free days, at Perry 6 Nw, IL.
What growing zone is Griggsville in?
Zone 6a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −7°.
What is the best time of year to visit Griggsville?
By one simple rule (highs of 62–84° and lows of 40° or more), April, May, June, September and October. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Griggsville getting warmer?
Yes: 1991–2020 averaged 0.7° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 93% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Griggsville.
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.