Rough River Lake, Kentucky climate: Climate normals at a NOAA weather station
Rough River Lake's normal year runs from 24°F January nights to 90°F July afternoons, with 51.5 inches of precipitation and 4 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 13.7°C, January lows of −4°C, July highs of 32°C, 1,307 mm of precipitation a year.
- NOAA stationRough River Lake
- Station IDUSC00156988
- Location37.62°N 86.50°W
- Elevation560 ft (171 m)
On October 23, the normal high in Rough River Lake is 69°F and the normal low 42°F, and the chance of measurable rain or snow is 25%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Rough River Lake.
- Jan 44° 24°
- Feb 49° 26°
- Mar 58° 34°
- Apr 70° 43°
- May 79° 53°
- Jun 87° 62°
- Jul 90° 65°
- Aug 90° 63°
- Sep 84° 56°
- Oct 72° 44°
- Nov 59° 34°
- Dec 48° 28°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like at Rough River Lake each month?
July is the warmest month, with normal highs of 90°F; January the coldest, with normal lows of 24°F. The most precipitation falls in May (6.00 in), the least in August (3.24 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 44°F | 24°F | 34.0°F | 3.60 | 2.1 | 9 | <1 | 25 | 9 h 50 min |
| February | 49°F | 26°F | 37.4°F | 3.85 | 1.4 | 9 | <1 | 22 | 10 h 50 min |
| March | 58°F | 34°F | 45.9°F | 4.46 | 0.2 | 10 | <1 | 17 | 11 h 50 min |
| April | 70°F | 43°F | 56.4°F | 5.30 | 0.2 | 10 | <1 | 7 | 13 h 10 min |
| May | 79°F | 53°F | 65.7°F | 6.00 | 0.0 | 11 | 2 | 1 | 14 h 10 min |
| June | 87°F | 62°F | 74.1°F | 4.78 | 0.0 | 9 | 10 | <1 | 14 h 40 min |
| July | 90°F | 65°F | 77.8°F | 4.20 | 0.0 | 8 | 18 | <1 | 14 h 30 min |
| August | 90°F | 63°F | 76.5°F | 3.24 | 0.0 | 7 | 16 | <1 | 13 h 40 min |
| September | 84°F | 56°F | 69.9°F | 3.48 | 0.0 | 7 | 7 | <1 | 12 h 30 min |
| October | 72°F | 44°F | 58.1°F | 4.06 | 0.0 | 7 | 1 | 6 | 11 h 20 min |
| November | 59°F | 34°F | 46.5°F | 3.84 | 0.1 | 8 | <1 | 16 | 10 h 10 min |
| December | 48°F | 28°F | 37.8°F | 4.66 | 0.4 | 10 | <1 | 23 | 9 h 40 min |
| Year (annual) | 69°F | 44°F | 56.7°F | 51.47 | 4.4 | 105 | 54 | 117 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 6°C | −4°C | 1.1°C | 91 mm | 5 cm |
| February | 9°C | −3°C | 3.0°C | 98 mm | 4 cm |
| March | 15°C | 1°C | 7.7°C | 113 mm | 1 cm |
| April | 21°C | 6°C | 13.6°C | 135 mm | 1 cm |
| May | 26°C | 12°C | 18.7°C | 152 mm | 0 cm |
| June | 30°C | 16°C | 23.4°C | 121 mm | 0 cm |
| July | 32°C | 19°C | 25.4°C | 107 mm | 0 cm |
| August | 32°C | 17°C | 24.7°C | 82 mm | 0 cm |
| September | 29°C | 13°C | 21.1°C | 88 mm | 0 cm |
| October | 22°C | 7°C | 14.5°C | 103 mm | 0 cm |
| November | 15°C | 1°C | 8.1°C | 98 mm | 0 cm |
| December | 9°C | −2°C | 3.2°C | 118 mm | 1 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00156988; 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.
Which months are mildest at Rough River Lake?
Normal highs sit between 65°F and 85°F in April, May, September and October. Of those, September has the fewest days with rain (7).
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 USC00156988.
When is the last frost at Rough River Lake?
In Rough River Lake, the last spring frost (32°F) comes after April 17 in half of years and after May 5 in one year in ten; the first autumn frost comes before October 23 in half of years and before October 8 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 171 year in 10 after May 5; 9 in 10 after March 31
- First autumn frost, half of years before
- October 231 year in 10 before October 8; 9 in 10 before November 3
NOAA puts the median frost-free season at 187 days, and the season without a hard freeze (28°F) at 211 days.
A hard freeze (28°F) comes after April 3 in half of springs and before November 1 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Rough River Lake in zone 7a in ZIP code 40119, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, the station is in zone 6b: the coldest night of a typical year reaches −1°F (18 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 USC00156988; 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 at Rough River Lake?
In a normal year in Rough River Lake, 54 days a year reach 90°F (2 of them 100°F or more), 117 nights fall to 32°F or colder and 105 days bring measurable precipitation.
- Days at 90°F or more
- 54a normal year
- Days at 100°F or more
- 2a normal year
- Nights at 32°F or colder
- 117a normal year
- Days that stay below freezing
- 14high of 32°F or less
- Days with 0.01 inch of precipitation
- 105a normal year
- Days with 1 inch of snow or more
- 2a normal year
The highest temperature in this station's record (since 1947) is 110°F, on June 30, 2012; the lowest is −25°F, on January 24, 1963.
The wettest calendar year on that record is 1979, with 72.26 in; the snowiest season is 1969–70, with 24.3 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00156988; records: ACIS (NOAA Regional Climate Centers), station USC00156988. Records use complete months only; a month missing more than three days is left out.
How sunny is it at Rough River Lake?
Over a year 74% of the sunlight that would reach the ground under clear skies gets through the clouds at Rough River Lake, 4.2 kWh per square metre a day. August is the sunniest month (81%) and December the cloudiest (62%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 63% | 2.0 |
| February | 62% | 2.7 |
| March | 66% | 3.8 |
| April | 73% | 5.1 |
| May | 74% | 5.7 |
| June | 81% | 6.4 |
| July | 81% | 6.1 |
| August | 81% | 5.6 |
| September | 79% | 4.7 |
| October | 75% | 3.5 |
| November | 72% | 2.5 |
| December | 62% | 1.8 |
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 many heating and cooling degree days does Rough River Lake record?
A normal year at Rough River Lake brings 4,418 heating degree days, 18% fewer than the median U.S. place (5,373), and 1,421 cooling degree days, 57% more than the median (908). Five months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 4,235 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 961 | 0 |
| February | 772 | 0 |
| March | 597 | 5 |
| April | 287 | 31 |
| May | 97 | 118 |
| June | 9 | 282 |
| July | 0 | 397 |
| August | 1 | 359 |
| September | 40 | 186 |
| October | 251 | 39 |
| November | 560 | 3 |
| December | 843 | 0 |
| Year (annual) | 4,418 | 1,421 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00156988. 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.
Have recent years at Rough River Lake been warmer than normal?
2023 averaged 57.7°F, 1.0°F above the 1991-2020 normal of 56.7°F. 2 of the 3 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 57.1°F | +0.4°F | 56.08 | 4.7 |
| 2022 | 56.0°F | −0.7°F | 48.67 | 8.4 |
| 2023 | 57.7°F | +1.0°F | 51.09 | 0.1 |
Over 39 complete years from 1966 to 2023, the station's annual mean temperature rose at a fitted 3.9°F per century (+0.22°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00156988; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Rough River Lake's climate compare?
Rough River Lake is warmer than 42 of the 68 places with their own NOAA record in Kentucky, and wetter than 34. Across the 7,247 U.S. stations with normals, its annual mean of 56.7°F is warmer than 66%.
In the Köppen classification computed from these normals, Rough River Lake 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.
Questions about Rough River Lake's climate
What is the coldest month at Rough River Lake?
January, with a normal high of 44°F and a normal low of 24°F. The warmest is July (90°F by day, 65°F at night).
Does it snow at Rough River Lake?
Yes: 4 inches in a normal year, falling on 6 days with 0.1 inch or more, the most in January (2.1 inches).
What is the rainiest month at Rough River Lake?
May, with 6.00 in of precipitation in a normal year; the driest is August with 3.24 in.
What plant hardiness zone is Rough River Lake in?
The USDA's 2023 map puts Rough River Lake in zone 7a in ZIP code 40119, the nearest ZIP area. By the same method at the station, the coldest night of a typical year reaches −1°F (18 years, 1991-2020): zone 6b.
How late can frost come at Rough River Lake?
In half of years the last 32°F night comes after April 17; in one year in ten it comes after May 5. Waiting until May 5 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Kentucky climateThe statewide normals and every place in the state
- McDaniels, KY4 miles from this station, 55.4°F a year
- Leitchfield, KY14 miles from this station, 53.8°F a year
- Corners, KY19 miles from this station, 54.4°F a year
- Cannelton, IN22 miles from this station, 57.3°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made