Florissant weather in May

In May, Florissant sees average daytime highs of 75°F and overnight lows near 58°F, with 5.0 in of rain across 13.5 wet days and about 14.1 hours of daylight. It is the 5th-warmest and 1st-wettest month of the year here.

Highs climb over the month, from about 71°F in the first days to 79°F by the end. The sky is clear or mostly clear about 27% of the time in May, and the air most often feels dry.

Daylight stretches from about 13 h 36 min at the start of May to 14 h 30 min by month's end. Set against the rest of the year, May is Florissant's 8th-clearest and 8th-windiest month. For the whole year in context, see Florissant's year-round climate.

Daytime high
75°
5th warmest
Overnight low
58°
8th coldest
Rainfall
5.0 in
13.5 wet days
Daylight
14 h 06 min
4:54 AM – 7:01 PM
Cloud cover
62%
8th clearest
Wind
7 mph
8th windiest
Solar energy
5.8 kWh/m²
Travel score
6.2
out of 10

Florissant is city in St. Louis County, Missouri, United States.

Density
1,561/km²
people per km²
Founded
1785

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

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 71°F in the first days to 79°F by the end.

A typical May day in Florissant reaches about 75°F in the afternoon and slips back to 58°F overnight — a 17°F spread between the day's warmth and the night's chill. On most days the high lands between 63°F and 86°F. Set against its neighbours, May runs about 9°F warmer than April and about 9°F cooler than June.

40°60°80°151015202531
Avg high (°F)Avg low (°F)
17153
27153
37153
47254
57254
67255
77355
87355
97356
107456
117456
127456
137457
147557
157557
167558
177658
187658
197659
207759
217760
227760
237860
247861
257861
267861
277962
287962
297962
308063
318063

How May really feels in Florissant

Once humidity and wind are folded in, May averages 0 days that feel above 90°F and 0 that feel at or below 32°F — the comfort signal a plain temperature reading hides.

Days feeling ≥ 90°F
0
heat index over the day's high
Days feeling ≤ 32°F
0
wind chill below the day's low

May sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Florissant weather by month

How May compares with the rest of the year at a glance. May is the 5th-warmest and 1st-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan39° / 24°2.88.22.99.60.0
Feb44° / 28°2.57.72.810.50.8
Mar55° / 37°3.710.51.411.73.5
Apr66° / 47°4.611.20.2135.8
May75° / 58°5.013.5014.16.2
Jun84° / 67°4.211014.75.4
Jul87° / 70°3.49.9014.44.7
Aug86° / 68°2.99.2013.55.2
Sep79° / 60°3.37.6012.37.1
Oct67° / 48°3.48.40.1116.6
Nov54° / 37°3.68.60.89.93.4
Dec43° / 29°2.68.22.29.30.6

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 27% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 16% of May, with mostly cloudy or overcast conditions the remaining 57%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14258
24357
34357
44357
54258
64258
74258
84258
94258
104357
114357
124456
134456
144456
154456
164357
174456
184456
194456
204357
214357
224258
234357
244258
254357
264357
274357
284456
294357
304456
314654

Chance of precipitation in May

Any precipitation

Florissant gets around 5.0 in of rain over 13.5 wet days in May, the wettest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 43% and peaks near 46% on the wettest days.

0%20%40%60%151015202531
Rain chance (%)
146
246
345
445
545
645
745
844
944
1044
1144
1243
1343
1443
1543
1643
1743
1843
1943
2043
2143
2243
2343
2442
2542
2641
2741
2841
2940
3039
3139

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

Most of May feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, May lands in the dry band about 50% of days. Sticky, muggy-or-worse air turns up on roughly 15% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
170181020
269181120
366191230
465191330
563191440
662191540
760191650
859191750
958181860
1056181970
1155172080
1254172090
13531621100
14521621110
15521521120
16511521130
17511421140
18491421150
19481421170
20461422181
21451422191
22431422211
23411422221
24401522231
25381521242
26361621252
27351721252
28331721262
29321821272
30301921282
31291921283

Wind in May

Winds average 7 mph in May.

Across May, daily wind ranges from about 7 mph on the calmest days to 8 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (mph)Feels
18light breeze
28light breeze
38light breeze
48light breeze
58light breeze
68light breeze
78light breeze
87light breeze
97light breeze
107calm
117calm
127calm
137calm
147calm
157calm
167calm
177calm
187calm
197calm
207calm
217calm
227calm
237calm
247calm
257calm
267calm
277calm
287calm
297calm
307calm
317calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 13 h 36 min at the start of May to 14 h 30 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 54 minutes over May. Sunrise moves from 5:10 AM to 4:44 AM, and sunset from 6:46 PM to 7:13 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.65:106:46
213.65:096:47
313.75:086:48
413.75:076:49
513.75:066:50
613.85:056:51
713.85:036:52
813.85:026:53
913.95:016:54
1013.95:006:55
1114.04:596:56
1214.04:586:57
1314.04:576:58
1414.04:566:59
1514.14:557:00
1614.14:547:01
1714.14:537:02
1814.24:537:03
1914.24:527:03
2014.24:517:04
2114.34:507:05
2214.34:497:06
2314.34:497:07
2414.34:487:08
2514.44:477:09
2614.44:477:09
2714.44:467:10
2814.44:467:11
2914.44:457:12
3014.54:457:13
3114.54:447:13

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.8 kWh/m².

For context, solar energy here swings from a low near 1.9 kWh/m² to a high of 6.43 kWh/m² in June across the year — May's 5.8 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.4Bright
25.4Bright
35.4Bright
45.5Bright
55.5Bright
65.5Bright
75.6Bright
85.6Bright
95.6Bright
105.7Bright
115.7Bright
125.8Bright
135.8Bright
145.8Bright
155.8Bright
165.8Bright
175.9Bright
185.9Bright
195.9Bright
205.9Bright
216.0Bright
226.0Bright
236.0Bright
246.0Bright
256.0Intense
266.0Intense
276.0Intense
286.0Intense
296.0Intense
306.1Intense
316.1Intense
Planning a trip in May

Hazard calendar for Florissant

In seasonPeak

None of Florissant's seasonal hazards are active in May. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.

Florissant sits in the Atlantic hurricane belt; the season peaks August–October.

Atlantic hurricane
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is May a good time to visit Florissant?

Our two travel scores rate May for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

6.2
Sightseeing
3rd-best month of the year
5.3
Beach & pool
5th-best month of the year

May is a reasonable time to visit Florissant for sightseeing.

What to pack for Florissant in May

From May's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In May, Florissant sees daytime highs around 75°F and nights near 58°F. Worth packing: light clothes, rain gear and sun protection. About 14 days see rain.

light clothesrain gearsun protection

UV index in Florissant in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 8 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Florissant peaks around June 23 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near January 1 at about 2 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 10 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highModerateJun 23UV 9Jan 1UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr7High
May8Very high
Jun9Very high
Jul9Very high
Aug8Very high
Sep7High
Oct4Moderate
Nov3Moderate
Dec2Low

Air quality in Florissant in May

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where May falls, not just the annual average.

Air quality in Florissant is worst in August — around 18 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (October, 8 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodModerateGoodAug 1018 µg/m³Oct 228 µg/m³
PM2.5 (µg/m³)Level
Jan10Good
Feb13Moderate
Mar13Moderate
Apr11Good
May14Moderate
Jun16Moderate
Jul18Moderate
Aug18Moderate
Sep13Moderate
Oct8Good
Nov9Good
Dec10Good
Location & terrain

Where is Florissant?

Florissant sits at 38.8°N, 90.3°W, 574 ft above sea level, in United States. The nearest listed city is Hazelwood, 3.1 mi away.

Topography around Florissant

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

Within 2 miles, the terrain around Florissant has only modest variations in elevation — a maximum elevation change of 190 ft around an average of 554 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 577 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 863 ft.

The land around Florissant is covered by trees (48%) and artificial surfaces (37%) within 2 miles, trees (36%), cropland (23%) and artificial surfaces (21%) within 10 miles, and trees (44%) and cropland (41%) within 50 miles.

2 miles
190 ft
10 miles
577 ft
50 miles
863 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
May weather nearby: Hazelwood 3.1 mi · Ferguson 3.1 mi · Old Jamestown 3.7 mi · Spanish Lake 5.6 mi · Overland 6.2 mi · Maryland Heights 8.1 mi · Saint Charles 8.7 mi · University City 9.3 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 Florissant (38.7892°, -90.3226°, elevation 574 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. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). 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).