Grayson, Kentucky climate: Normal weather by month, frost dates and records
Grayson's normal year runs from 22°F January nights to 87°F July afternoons, with 46.1 inches of precipitation and 18 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 12.2°C, January lows of −6°C, July highs of 30°C, 1,172 mm of precipitation a year.
- NOAA stationGrayson (2 mi E)
- Station IDUSC00153389
- Location38.34°N 82.91°W
- Elevation580 ft (177 m)
- Population3,702
On October 23, the normal high in Grayson is 67°F and the normal low 37°F, and the chance of measurable rain or snow is 31%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Grayson.
- Jan 43° 22°
- Feb 47° 24°
- Mar 57° 29°
- Apr 69° 39°
- May 76° 49°
- Jun 84° 58°
- Jul 87° 63°
- Aug 86° 62°
- Sep 80° 54°
- Oct 69° 41°
- Nov 57° 31°
- Dec 47° 26°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Grayson each month?
July is the warmest month, with normal highs of 87°F; January the coldest, with normal lows of 22°F. The most precipitation falls in May (4.89 in), the least in October (2.92 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 43°F | 22°F | 32.4°F | 3.25 | 5.9 | 13 | <1 | 26 | 9 h 50 min |
| February | 47°F | 24°F | 35.3°F | 3.28 | 6.1 | 13 | <1 | 24 | 10 h 50 min |
| March | 57°F | 29°F | 42.9°F | 4.46 | 1.8 | 13 | <1 | 20 | 11 h 50 min |
| April | 69°F | 39°F | 53.6°F | 4.08 | 0.1 | 12 | <1 | 9 | 13 h 10 min |
| May | 76°F | 49°F | 62.7°F | 4.89 | 0.0 | 13 | 1 | 1 | 14 h 10 min |
| June | 84°F | 58°F | 71.0°F | 4.00 | 0.0 | 12 | 5 | <1 | 14 h 50 min |
| July | 87°F | 63°F | 74.8°F | 4.78 | 0.0 | 12 | 9 | <1 | 14 h 40 min |
| August | 86°F | 62°F | 73.6°F | 4.69 | 0.0 | 10 | 9 | <1 | 13 h 40 min |
| September | 80°F | 54°F | 66.9°F | 3.05 | 0.0 | 8 | 3 | <1 | 12 h 30 min |
| October | 69°F | 41°F | 54.9°F | 2.92 | 0.0 | 9 | <1 | 6 | 11 h 20 min |
| November | 57°F | 31°F | 43.8°F | 2.95 | 0.4 | 10 | <1 | 19 | 10 h 10 min |
| December | 47°F | 26°F | 36.3°F | 3.78 | 3.8 | 14 | <1 | 24 | 9 h 30 min |
| Year (annual) | 67°F | 41°F | 54.0°F | 46.13 | 18.1 | 139 | 27 | 129 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 6°C | −6°C | 0.2°C | 83 mm | 15 cm |
| February | 8°C | −5°C | 1.8°C | 83 mm | 15 cm |
| March | 14°C | −1°C | 6.1°C | 113 mm | 5 cm |
| April | 20°C | 4°C | 12.0°C | 104 mm | 0 cm |
| May | 25°C | 10°C | 17.1°C | 124 mm | 0 cm |
| June | 29°C | 15°C | 21.7°C | 102 mm | 0 cm |
| July | 30°C | 17°C | 23.8°C | 121 mm | 0 cm |
| August | 30°C | 16°C | 23.1°C | 119 mm | 0 cm |
| September | 27°C | 12°C | 19.4°C | 77 mm | 0 cm |
| October | 21°C | 5°C | 12.7°C | 74 mm | 0 cm |
| November | 14°C | −1°C | 6.6°C | 75 mm | 1 cm |
| December | 8°C | −3°C | 2.4°C | 96 mm | 10 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00153389; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit Grayson?
Normal highs sit between 65°F and 85°F in April, May, June, September and October. Of those, September has the fewest days with rain (8).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00153389.
When is the last frost in Grayson?
In Grayson, the last spring frost (32°F) comes after April 27 in half of years and after May 15 in one year in ten; the first autumn frost comes before October 17 in half of years and before October 6 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- April 271 year in 10 after May 15; 9 in 10 after April 14
- First autumn frost, half of years before
- October 171 year in 10 before October 6; 9 in 10 before October 29
NOAA puts the median frost-free season at 172 days, and the season without a hard freeze (28°F) at 193 days.
A hard freeze (28°F) comes after April 15 in half of springs and before October 26 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Grayson in zone 6b in ZIP code 41143, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Grayson's NOAA station is in zone 7a: the coldest night of a typical year reaches 1°F (17 complete years); the map interpolates between stations and terrain, so the station and the ZIP area can differ by half a zone.
Frost dates for every NOAA station in Kentucky · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00153389; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
How hot and how cold does it get in Grayson?
In a normal year in Grayson, 27 days a year reach 90°F (1 of them 100°F or more), 129 nights fall to 32°F or colder and 139 days bring measurable precipitation.
- Days at 90°F or more
- 27a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 129a normal year
- Days that stay below freezing
- 16high of 32°F or less
- Days with 0.01 inch of precipitation
- 139a normal year
- Days with 1 inch of snow or more
- 7a normal year
Source: NOAA NCEI 1991-2020 annual normals, station USC00153389.
How sunny is Grayson?
Over a year 72% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Grayson, 4.0 kWh per square metre a day. August is the sunniest month (80%) and December the cloudiest (59%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 60% | 1.9 |
| February | 60% | 2.6 |
| March | 65% | 3.7 |
| April | 71% | 5.0 |
| May | 72% | 5.5 |
| June | 78% | 6.2 |
| July | 77% | 5.9 |
| August | 80% | 5.5 |
| September | 78% | 4.5 |
| October | 72% | 3.3 |
| November | 70% | 2.3 |
| December | 59% | 1.6 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does Grayson need?
A normal year in Grayson brings 4,952 heating degree days, 8% fewer than the median U.S. place (5,373), and 980 cooling degree days, 8% more than the median (908). Seven months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 3,536 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,010 | 0 |
| February | 832 | 0 |
| March | 687 | 2 |
| April | 354 | 13 |
| May | 139 | 67 |
| June | 17 | 196 |
| July | 1 | 305 |
| August | 2 | 267 |
| September | 60 | 117 |
| October | 326 | 13 |
| November | 636 | 0 |
| December | 890 | 0 |
| Year (annual) | 4,952 | 980 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00153389. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
How does Grayson's climate compare?
Grayson is warmer than 7 of the other 67 places with their own NOAA record in Kentucky, and wetter than 2. Across the 7,247 U.S. stations with normals, its annual mean of 54.0°F is warmer than 57%.
In the Köppen classification computed from these normals, Grayson is Cfa: temperate, no dry season, hot summer. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
What do Grayson's other NOAA stations record?
One more NOAA station keeps 1991-2020 normals in or near Grayson. This page uses Grayson (2 mi E); the other differs by site and elevation:
| Station | From this station | Elevation | Year | Jan low | Jul high | Precip. | Snow | Last frost |
|---|---|---|---|---|---|---|---|---|
| Grayson (3 mi SW) USC00153391 | 5 mi SW | 700 ft | 53.5°F | 21°F | 87°F | – | – | May 2 |
Source: NOAA NCEI 1991-2020 normals for each station. Last frost: the median last spring date of 32°F.
Questions about Grayson's climate
What is the coldest month in Grayson?
January, with a normal high of 43°F and a normal low of 22°F. The warmest is July (87°F by day, 63°F at night).
Does it snow in Grayson?
Yes: 18 inches in a normal year, falling on 15 days with 0.1 inch or more, the most in February (6.1 inches).
What is the rainiest month in Grayson?
May, with 4.89 in of precipitation in a normal year; the driest is October with 2.92 in.
What plant hardiness zone is Grayson in?
The USDA's 2023 map puts Grayson in zone 6b in ZIP code 41143, the nearest ZIP area. By the same method at Grayson's NOAA station, the coldest night of a typical year reaches 1°F (17 years, 1991-2020): zone 7a.
How late can frost come in Grayson?
In half of years the last 32°F night comes after April 27; in one year in ten it comes after May 15. Waiting until May 15 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Kentucky climateThe statewide normals and every place in the state
- Olive Hill, KY11 miles from this station, 52.3°F a year
- Warnock 2, KY12 miles from this station, 54.5°F a year
- Gimlet (9 mi N), KY15 miles from this station, 54.9°F a year
- Ashland, KY18 miles from this station, 53.8°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made