Climate and average weather in Mason

In Mason, the summers are humid, hot, showery, and partly cloudy and the winters are cold, snowy, and mostly cloudy.

Best: late August to mid October

Over the course of the year, the temperature in Mason typically varies from 25°F to 85°F, and is rarely below 5°F or above 92°F. July is the hottest month of the year, while January is the coldest.

Based on the travel score, the best times of year to visit Mason for warm-weather activities are from early May to mid June and late August to mid October.

Hottest
Jul
85°
Coldest
Jan
25°
Wettest
May
4.7 in
Driest
Sep
2.7 in
Rain / yr
43.4 in
126 wet days
Daylight
9.2–14.8 h
shortest–longest
Elevation
810 ft
39.4°N
Clearest
Sep
49% cloud

Mason is city in Warren County, Ohio, United States.

Density
676/km²
people per km²
Founded
1815

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Mason weather by month, at a glance

The whole year in one picture — sky, rain, humidity, temperature and travel score. Click any band to jump to its full chart.

Each stripe is one measure across the whole year, stacked so a single day reads top to bottom. The sky band runs overcast grey on top down to clear blue at the base — more blue means sunnier — followed by the rainfall curve, the humidity band, a temperature strip that tints each stretch of the year by how warm its average high is, and the travel-score line at the foot. Scan straight down any date to read that day across every measure at once; the score climbs highest around late August to mid October.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

Daily average highs and lows in Mason, from 1991–2020 of climate data. The shaded bands show the range most days fall in — 10th to 90th percentile.

The hot season lasts 4.5 months, from May 16 to September 28, with daily high temperatures above 73°F. The hottest month of the year in Mason is July, with an average high of 85°F and low of 68°F.

The cool season lasts 3.1 months, from November 30 to March 2, with daily high temperatures below 47°F. The coldest month of the year in Mason is January, with an average low of 25°F and high of 39°F.

Days typically run about 17°F warmer than nights, with the widest day–night swing (around 19°F) in April.

20°40°60°80°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°F)Avg low (°F)
Jan3925
Feb4227
Mar5235
Apr6546
May7356
Jun8265
Jul8568
Aug8366
Sep7859
Oct6547
Nov5337
Dec4330

How hot and cold Mason really feels

Feels-like highFeels-like lowactual air temp

The felt-temperature range through the year — heat index on the day's high (summer humidity), wind chill on the night's low (winter wind). The dashed lines are the plain thermometer; the gap is how much hotter or colder it really feels.

On the coldest nights, wind chill pulls the feels-like down to about 14°F (around January 21), with roughly 131 freezing days a year (feels-like at or below 32°F), worst in January.

20°40°60°80°JanFebMarAprMayJunJulAugSepOctNovDec
Feels-like high (°F)Air high (°F)Feels-like low (°F)Air low (°F)
Jan39391625
Feb42421927
Mar52522935
Apr65654246
May73735656
Jun82826565
Jul86856868
Aug84836666
Sep78785959
Oct65654447
Nov53533137
Dec43432230

Average hourly temperature in Mason

A compact picture of the whole year, hour by hour: each column is a day, each row an hour, and the color is the modeled average temperature. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

Read left to right for the day of the year and top to bottom for the hour of the day; the color is the modeled temperature, cool blues through to hot reds on the same scale as the other charts. A vertical slice is a single day's swing — coolest just before dawn, warmest in the mid-afternoon — while a horizontal slice follows one hour across the seasons. The darker overlay marks night and the lighter one the twilight around sunrise and sunset. Colors run warmest on July afternoons, near 85°F, and coldest before dawn in January, near 25°F.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM

Mason weather by month

Every month at a glance. Click a month for its detailed page.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan39° / 25°3.410.44.39.50.0
Feb42° / 27°3.09.43.810.50.4
Mar52° / 35°4.211.4211.72.7
Apr65° / 46°4.712.70.5135.3
May73° / 56°4.713.1014.16.2
Jun82° / 65°4.212.2014.75.8
Jul85° / 68°3.511.2014.55.3
Aug83° / 66°2.99.5013.55.9
Sep78° / 59°2.78012.37.2
Oct65° / 47°3.08.50.1116.1
Nov53° / 37°3.49.30.89.83.0
Dec43° / 30°3.810.42.99.30.4

Chance of rain

How likely it is to rain on a typical day, and how that shifts across the wetter and drier seasons.

Mason gets about 43.4 in of precipitation a year. On a typical day the chance of rain is often wet, but that rises and falls sharply with the seasons.

The wetter season lasts 5.2 months, from around Feb 23 to Jul 30, peaking in May at about 45% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Oct 4.

May is the wettest month by volume, with 4.7 in over about 13 wet days; September is the driest, with 2.7 in. Some of the cold-season precipitation falls as snow.

0%10%20%30%40%50%60%JanFebMarAprMayJunJulAugSepOctNovDecdrierwetterdriermostly drysome rainoften wetvery wetMay 5 · 45%Oct 4 · 24%
Rain on a day (%)Rain days
Jan3410
Feb339
Mar3711
Apr4213
May4213
Jun4012
Jul3611
Aug3110
Sep268
Oct289
Nov319
Dec3410

Monthly rainfall

Over a full year, Mason collects about 43.4 in of rain across 126 wet days — roughly 3.6 in in an average month.

It doesn’t fall evenly. May is the wettest month with 4.7 in, while September is the driest at just 2.7 in. The three wettest months alone bring about 31% of the year’s total, and some of the cold-season precipitation falls as snow.

0123456JanFebMarAprMayJunJulAugSepOctNovDec3.43.04.24.74.74.23.52.92.73.03.43.8
Rainfall (in)Rain daysSnow days
Jan3.4104
Feb3.094
Mar4.2112
Apr4.7131
May4.7130
Jun4.2120
Jul3.5110
Aug2.9100
Sep2.780
Oct3.090
Nov3.491
Dec3.8103

Snow in Mason

Average snowy days through the year, the snow-season span, and estimated snowfall — for ski trips and the perennial 'will there be snow at Christmas?' question.

Mason averages about 14 snowy days a year. Snow season runs roughly Nov 6 to Apr 11 — about 5.2 months.

January is snowiest, with roughly 4 days of snow and an estimated 8 in of snowfall. Over the year that adds up to an estimated 27 in of snow.

0246JanFebMarAprMayJunJulAugSepOctNovDecsnow seasonsnow seasonJan 18
Snow daysSnowfall (in)
Jan48
Feb48
Mar24
Apr10
May00
Jun00
Jul00
Aug00
Sep00
Oct00
Nov11
Dec36

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

How often the daytime sky is clear, partly cloudy or overcast.

In Mason, the average share of the sky covered by clouds shows significant seasonal variation over the course of the year.

The clearer part of the year begins around May 30 and lasts for 5.4 months, ending around November 10. The clearest month is September, when the sky is clear, mostly clear, or partly cloudy 59% of the time on average.

The cloudier part of the year begins around November 11 and lasts for 6.6 months, ending around May 29. The cloudiest month is December, when it is overcast or mostly cloudy 70% of the time.

0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%JanFebMarAprMayJunJulAugSepOctNovDecSep 2 · 60%Dec 13 · 28%clearmostly clearpartly cloudymostly cloudyovercastcloudierclearercloudier
Clearer (%)Cloudier (%)
Jan3070
Feb3268
Mar3565
Apr3961
May3961
Jun4852
Jul5347
Aug5743
Sep5941
Oct5149
Nov4060
Dec3070

Daylight, sunrise and sunset

DaylightNight

Hours of daylight through the year, with sunrise and sunset times.

The gold band is daylight — sunrise runs along its lower edge, sunset along the upper — so it widens toward summer and pinches toward winter, with night the dark area above and below. The longest day, around June 15, brings about 14 h 48 min of light; the shortest, around December 15, only 9 h 12 min — a swing of roughly 5 h 36 min.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan9.58:015:32
Feb10.57:386:06
Mar11.76:566:37
Apr13.06:077:08
May14.15:297:38
Jun14.75:158:00
Jul14.55:277:58
Aug13.55:557:28
Sep12.36:246:39
Oct11.06:545:51
Nov9.87:285:17
Dec9.37:565:11

Sunny days

How many genuinely sunny days each month brings — days the sky stays clear or mostly clear — banded into plain-language zones.

Mason averages about 9 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 5 and 13 days.

The sunnier stretch runs 5.0 months, from around Jun 18 to Nov 16. The sunniest month is September, with roughly 13 sunny days (mixed).

The greyest month is December, down near 6 sunny days — about 54% fewer than the September peak.

05101520JanFebMarAprMayJunJulAugSepOctNovDecgreyersunniergreyergloomymixedbrightSep 613 daysDec 125 days
Sunny daysSky
Jan6Gloomy
Feb6Gloomy
Mar7Gloomy
Apr7Gloomy
May7Gloomy
Jun8Mixed
Jul10Mixed
Aug12Mixed
Sep13Mixed
Oct11Mixed
Nov8Mixed
Dec6Gloomy

Humidity comfort

DryComfortableHumidMuggyOppressiveMiserable

Share of days at each humidity comfort level, based on the dew point — the measure that tracks how muggy it actually feels.

Humidity comfort is graded by the dew point — the temperature at which the air would be fully saturated — because it tracks how muggy it actually feels far better than relative humidity does. A low dew point feels dry and crisp; a high one feels sticky and oppressive no matter the reading on a humidity gauge.

In Mason, how humid it feels changes dramatically over the year.

The more humid part of the year lasts 4.4 months, from around May 14 to September 24. The muggiest month is July, when the air feels humid, muggy or worse about 77% of the time.

The most comfortable stretch runs from around September 25 to May 13, and January is the most comfortable month — the air is dry or comfortable 100% of the time.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecJan 19 · 100%Jul 19 · 20%oppressivemuggydrycomfortablehumidcomfortablehumidcomfortable
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
Jan991000
Feb991000
Mar973000
Apr889300
May56171790
Jun221823326
Jul715243420
Aug1022242816
Sep402317163
Oct8211620
Nov963000
Dec991000

Wind

Average wind speed through the year, banded into plain-language speed zones so a number reads as 'breezy' or 'calm' without knowing the scale.

This is the average sustained wind speed at the standard 10 metres above open ground — the steady flow a weather station reports, not the sharper gusts that come and go, which can run half again as fast. It's the number that says whether a place is generally breezy or calm.

Across the year, average wind speed in Mason is typically calm, near 7 mph, and varies moderately with the seasons.

The windier part of the year lasts 6.9 months, from around Oct 17 to May 15. The windiest month is April, averaging about 8 mph (light breeze).

The calmer part of the year runs from around May 16 to Oct 16, with August the calmest month at about 5 mph.

051015JanFebMarAprMayJunJulAugSepOctNovDecwindiercalmerwindiercalmlight breezebreezyApr 11 · 8 mphAug 5 · 5 mph
Wind speed (mph)Feels
Jan8light breeze
Feb8light breeze
Mar8light breeze
Apr8light breeze
May7calm
Jun6calm
Jul5calm
Aug5calm
Sep6calm
Oct7calm
Nov8light breeze
Dec8light breeze

Best time to visit Mason

TravelBeach/poolTemperatureCloudsPrecipitation

To characterize how pleasant the weather is in Mason throughout the year, we compute two travel scores — one for general sightseeing, one for beach and pool weather.

Around late August, Mason is still near the start of its best-weather window — great conditions with the peak-season crowds not yet at full swing.

Inferred from the travel-score curve; month-by-month visitor numbers are a planned addition.

The travel score favors clear, rainless days with daytime highs between 64°F and 82°F. Based on this score, the best times of year to visit Mason for general outdoor tourist activities run from early May to mid June and again from late August to late October, with a peak score in the last week of September.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timebest timetravel scoretemperaturecloudsprecipitationSep 24 · 7.4

The travel score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

Travel score (0–10)Rating
Jan0.0poor
Feb0.4poor
Mar2.7poor
Apr5.3fair
May6.2good
Jun5.8good
Jul5.3fair
Aug5.9good
Sep7.1good
Oct6.1good
Nov3.0poor
Dec0.4poor

The beach/pool score favors clear, rainless days with daytime highs between 75°F and 93°F. Based on this score, the best time of year to visit Mason for hot-weather activities is from late May to late September, with a peak score in the third week of August.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebeach/pool scoretemperaturecloudsprecipitationAug 21 · 7.1

The beach/pool score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

What to pack for Mason, by month

EssentialRecommendedOptional

Month by month, what's worth putting in the bag — from the temperature range, rain chance, sun and wind. Tap a month for a quick packing note.

For a warm-season trip around July (highs near 85°F), the essentials are light clothes, rain gear and sun protection. In the cold season around January (highs near 39°F), pack a warm layer, a heavy coat and rain gear.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In July, Mason sees daytime highs around 85°F and nights near 68°F. Pack light clothes and sun protection. Worth having: rain gear. About 11 days see rain.

UV index (midday) in Mason by month

LowModerateHighVery highExtreme

Clear-sky midday UV index through the year, shaded by the WHO exposure levels — how much sun protection each month calls for.

Under clear skies, the midday UV index in Mason peaks around June 21 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 at about 2 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighModerateJun 21UV 9Dec 22UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr6High
May8Very high
Jun9Very high
Jul9Very high
Aug8Very high
Sep6High
Oct3Moderate
Nov3Moderate
Dec2Low

Average hourly UV index in Mason

LowModerateHighVery highExtreme

Modeled clear-sky UV for every hour of every day — when in the day sun protection actually matters.

The whole year hour by hour: each column is a day, each row an hour, and the color is the modeled clear-sky UV index — the midday peak scaled down as the sun sits lower in the sky. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

UV falls off far faster than brightness as the sun drops, so even in June the burn window is concentrated in the middle of the day: about 8.5 hours a day reach index 3 (protection recommended), and 5.5 hours reach 6 or more. Mornings and late afternoons stay comparatively gentle year round.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM
UV ≥ 3 (h/day)UV ≥ 6 (h/day)
Jan00
Feb00
Mar50
Apr60.5
May84.5
Jun8.55.5
Jul8.55.5
Aug7.54
Sep61.5
Oct2.50
Nov00
Dec00

Air quality in Mason by month

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see which months the air is worst, not just the yearly average.

Air quality in Mason is worst in July — around 19 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (October, 8 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1418 µg/m³Oct 248 µg/m³
PM2.5 (µg/m³)Level
Jan10Good
Feb11Good
Mar11Good
Apr12Good
May15Moderate
Jun18Moderate
Jul19Moderate
Aug16Moderate
Sep13Moderate
Oct8Good
Nov9Good
Dec9Good
Almanac & agriculture

Growing season

Chance of a frost-free dayTypical season (≥50%)

The growing season in Mason typically lasts about 273 days, from around March 7 to December 4 — the span where a frost-free day is more likely than not. It is reliably frost-free from April 13 to October 28.

0%25%50%75%100%JanFebMarAprMayJunJulAugSepOctNovDecgrowing seasonMar 750%Apr 1390%Oct 2890%Dec 450%
Frost-free chance (%)Frost nights
Jan2831
Feb3328
Mar6231
Apr9210
May1000
Jun1000
Jul1000
Aug1000
Sep1000
Oct951
Nov7130
Dec4131

Growing degree days

Degree days (base 50°F)Frost-free shaded

Growing degree days tally heat above 50°F: each day adds however many degrees its average temperature runs over that threshold, and cold days add nothing. Mason banks about 3,620 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around July.

01,0002,0003,0004,000JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°F·days)
Jan0
Feb0
Mar0
Apr155
May450
Jun691
Jul814
Aug769
Sep545
Oct195
Nov0
Dec0

Solar energy

Average daily shortwave solar energy reaching the ground, banded into brightness zones so the number means something at a glance.

Solar energy is how much sunlight actually reaches the ground each day, measured in kilowatt-hours per square metre (kWh/m²) — the combined effect of how long the sun is up, how high it climbs, and how much cloud gets in the way. It's the raw fuel a solar panel has to work with: for scale, 1 kWh/m² a day is dim and wintry, while 7+ is desert-bright.

Mason receives about 4.1 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 1.7 and 6.3 kWh/m².

The brighter stretch of the year lasts 6.3 months, from around Mar 20 to Sep 27. The brightest month is June, averaging about 6.2 kWh/m² (intense).

The dimmest month is December, down near 1.7 kWh/m² — roughly 72% less than the June peak.

01234567JanFebMarAprMayJunJulAugSepOctNovDecdimmerbrighterdimmerdimmoderatebrightintenseJun 296.3 kWhDec 171.7 kWh
Solar energy (kWh/m²)Level
Jan2.0Moderate
Feb2.9Moderate
Mar4.0Moderate
Apr5.1Bright
May5.7Bright
Jun6.2Intense
Jul6.1Intense
Aug5.6Bright
Sep4.6Bright
Oct3.3Moderate
Nov2.3Moderate
Dec1.7Dim

Where is Mason?

Mason sits at 39.4°N, 84.3°W, 810 ft above sea level, in United States. The nearest listed city is Lebanon, 7.5 mi away.

Topography around Mason

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Mason.

Within 2 miles, the terrain around Mason has only modest variations in elevation — a maximum elevation change of 240 ft around an average of 817 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 492 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 912 ft.

The land around Mason is covered by grassland (39%), trees (36%) and artificial surfaces (22%) within 2 miles, trees (43%) and grassland (29%) within 10 miles, and trees (42%) and cropland (36%) within 50 miles.

2 miles
240 ft
10 miles
492 ft
50 miles
912 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
Nearby: Lebanon 7.5 mi · Forest Park 11 mi · Middletown 12 mi · Fairfield 14 mi · Hamilton 14 mi · Springboro 14 mi · Norwood 16 mi · White Oak 19 mi

United States travel facts

Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 100% of US
price level, 2025
GDP per capita
$90,027
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
98%
of population, 2024
Homicide rate
5.8
per 100k, 2023
Road deaths
12.7
per 100k/yr, 2019
Income group
High
World Bank
Religion
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Mason (39.3601°, -84.3099°, elevation 810 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).