Summers in Grassflat are cooler than in 84% of U.S. towns
The coldest hours of a January night bottom out at 18° on average. The seasons are far apart: from a winter night to a summer afternoon the average spans 64°. In January, nights here are colder than in 71% of U.S. towns. The heating season runs November to April: each of those months averages under 50°.
A year in Grassflat at a glance
Each month’s typical high and low, and what it brings.
What stands out about Grassflat’s climate
Compared with towns across the U.S., with Grassflat’s place in Pennsylvania beside it.
What a year in Grassflat feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 130 frost-free days a year
In half of years the last 32° night comes by May 21 and the first by September 27. Frost and day counts come from NOAA’s station at Clarence, PA, 9 miles from the town’s center, 160 ft lower.
The 2023 USDA map puts Grassflat’s center in zone 6a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −6°. 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 50 inches of snow a winter
Snow, measured at Clarence, PA, falls mostly in January. Precipitation (rain plus melted snow) adds up to 43 inches a year; September is the wettest month and February the driest. Rain or snow falls on about 157 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Grassflat
96% 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 Clarence, PA.
Living with Grassflat’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
130 frost-free days in zone 6a. The last frost comes by May 21 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 27.
Months with highs of 62–84° and lows of 40° or more: May, June, July, August and September.
Parks & trails →Of the yearly building losses FEMA expects in Grassflat from natural hazards, river flooding is the largest share (62%); heat waves, cold waves, winter storms and ice storms together are 12%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Grassflat and similar climates
TownRatings has no climate map of the towns around Grassflat yet.
Climates most like Grassflat’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 |
|---|---|---|---|---|
| Grassflat, PA | 18° | 82° | 43" | 50" |
| Ontario, OH | 17° | 82° | 42" | 49" |
| Sand Lake, NY | 15° | 82° | 43" | 53" |
| Topsfield, MA | 18° | 82° | 47" | 48" |
| South Hooksett, NH | 14° | 83° | 45" | 53" |
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 Grassflat averaged 0.8° warmer than the 1900s. The biggest change is in December (+2.0°).
A smaller shift than in 91% 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 Grassflat compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Grassflat’s place among Pennsylvania’s.
Grassflat weather by month
Highs, lows and precipitation from NOAA’s grid at Grassflat’s center; snow, wet days and snow on the ground from Clarence, PA. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 34° | 18° | 3.0" | 12.8" | 16 | 21 | 17° – 34° |
| February | 37° | 19° | 2.5" | 11.5" | 13 | 19 | 16° – 35° |
| March | 46° | 26° | 3.4" | 11.4" | 13 | 12 | 30° – 47° |
| April | 60° | 36° | 3.8" | 1.7" | 14 | 1 | 42° – 53° |
| May | 70° | 45° | 4.0" | 0.0" | 14 | 0 | 52° – 64° |
| June | 78° | 54° | 4.2" | 0.0" | 13 | 0 | 62° – 69° |
| July | 82° | 59° | 4.1" | 0.0" | 12 | 0 | 65° – 74° |
| August | 80° | 57° | 3.9" | 0.0" | 11 | 0 | 64° – 73° |
| September | 73° | 50° | 4.2" | 0.0" | 12 | 0 | 59° – 66° |
| October | 61° | 39° | 3.6" | 0.8" | 13 | 0 | 46° – 57° |
| November | 49° | 31° | 3.2" | 3.1" | 13 | 3 | 35° – 45° |
| December | 38° | 24° | 3.3" | 9.0" | 15 | 13 | 21° – 41° |
| Year | 59° | 38° | 43.0" | 50.3" | 157 | 70 |
How much a month can swing
A normal is an average. December swings the most: from 1991 to 2020 its average ranged from 21° to 41°. June is the most reliable, staying within 7°.
Where Grassflat’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 Grassflat’s center.
- Snow: Clarence, PA.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Clarence, PA, 9 miles from the town’s center, 160 ft lower; 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 Grassflat’s climate
What is the weather like in Grassflat?
A typical July afternoon reaches 82°, a January night drops to 18°, and about 50 inches of snow falls in a normal winter. Colder January nights than 71% of U.S. towns; cooler July afternoons than 84% of U.S. towns.
How cold does it get in Grassflat in winter?
January nights average 18°. About 175 nights a year reach 32° or below and 13 reach 0° or below. In the coldest January of the last 30 years the month averaged 17°.
How much snow does Grassflat get?
About 50 inches in a normal winter at Clarence, PA, most of it in January, with snow on the ground about 70 days a year.
How hot does it get in Grassflat?
July, with a typical high of 82° and a low of 59°. About 6 days a year reach 90° (Clarence, PA).
When is the first and last frost in Grassflat?
In half of years the last spring frost (32°) comes by May 21 and the first fall frost by September 27, about 130 frost-free days, at Clarence, PA.
What growing zone is Grassflat in?
Zone 6a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −6°.
What is the best time of year to visit Grassflat?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June, July, August and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Grassflat getting warmer?
Yes: 1991–2020 averaged 0.8° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 91% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Grassflat.
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.