Merritt Island weather in December

In December, Merritt Island sees average daytime highs of 71°F and overnight lows near 62°F, with 1.9 in of rain across 6.5 wet days and about 10.2 hours of daylight. It is the 10th-warmest and 10th-wettest month of the year here.

Highs ease over the month, from about 72°F in the first days to 70°F by the end. The sky is clear or mostly clear about 37% of the time in December, and the air most often feels dry.

Daylight stretches from about 10 h 18 min at the start of December to 10 h 12 min by month's end. Set against the rest of the year, December is Merritt Island's 7th-clearest and 6th-windiest month. For the whole year in context, see Merritt Island's year-round climate.

Daytime high
71°
10th warmest
Overnight low
62°
3rd coldest
Rainfall
1.9 in
6.5 wet days
Daylight
10 h 12 min
7:13 AM – 5:25 PM
Cloud cover
54%
7th clearest
Wind
10 mph
6th windiest
Solar energy
3 kWh/m²
Travel score
7.1
out of 10

Merritt Island is census designated place in Brevard County, Florida, United States.

Density
284/km²
people per km²

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

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 72°F in the first days to 70°F by the end.

A typical December day in Merritt Island reaches about 71°F in the afternoon and slips back to 62°F overnight — a 9°F spread between the day's warmth and the night's chill. On most days the high lands between 62°F and 77°F. Set against its neighbours, December runs about 4°F cooler than November and about 2°F warmer than January.

40°50°60°70°80°151015202531
Avg high (°F)Avg low (°F)
17364
27364
37263
47263
57263
67263
77263
87263
97262
107162
117162
127162
137162
147162
157161
167161
177161
187061
197061
207061
217061
227061
237060
247060
257060
267060
277060
287060
296960
306960
316960

How December really feels in Merritt Island

Once humidity and wind are folded in, December 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

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

Merritt Island weather by month

How December compares with the rest of the year at a glance. December is the 10th-warmest and 10th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysDaylight (hours)Travel score
Jan69° / 58°2.36.910.46.9
Feb70° / 60°2.06.8117.0
Mar73° / 63°2.46.611.87.5
Apr77° / 67°1.96.812.77.6
May81° / 72°2.79.313.46.8
Jun84° / 76°4.918.313.84.5
Jul85° / 77°4.319.813.64.0
Aug85° / 78°5.321.5133.8
Sep83° / 77°6.019.812.24.4
Oct80° / 73°3.712.111.36.4
Nov75° / 66°1.87.510.67.4
Dec71° / 62°1.96.510.27.1

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 37% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 17% of December, with mostly cloudy or overcast conditions the remaining 46%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
16040
26040
35941
46040
56040
65941
75941
85842
95842
105743
115743
125545
135446
145446
155347
165248
175149
185149
195149
205149
215050
224951
235050
244951
255050
265050
275050
285050
295149
305248
315248

Chance of precipitation in December

Any precipitation

Merritt Island gets around 1.9 in of rain over 6.5 wet days in December. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 22% and peaks near 23% on the wettest days.

0%10%20%30%151015202531
Rain chance (%)
121
221
321
421
521
621
721
821
921
1021
1122
1222
1322
1422
1523
1623
1723
1823
1923
2023
2123
2223
2323
2422
2522
2622
2722
2822
2922
3021
3121

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, December lands in the dry band about 35% of days. Sticky, muggy-or-worse air turns up on roughly 28% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1281923274
2281923273
3291823273
4291723283
5301723283
6301622283
7311622293
8311622293
9321522293
10321521293
11321521283
12331521283
13341521283
14341620273
15351620273
16361620263
17361619253
18371619253
19371619243
20381619233
21381619233
22391619223
23391620223
24391620223
25391620223
26391620223
27381620223
28381620233
29381621232
30391621232
31391621232

Wind in December

Winds average 10 mph in December.

Across December, daily wind ranges from about 10 mph on the calmest days to 10 mph at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (mph)Feels
110light breeze
210light breeze
310light breeze
410light breeze
510light breeze
610light breeze
710light breeze
810light breeze
910light breeze
1010light breeze
1110light breeze
1210light breeze
1310light breeze
1410light breeze
1510light breeze
1610light breeze
1710light breeze
1810light breeze
1910light breeze
2010light breeze
2110light breeze
2210light breeze
2310light breeze
2410light breeze
2510light breeze
2610light breeze
2710light breeze
2810light breeze
2910light breeze
3010light breeze
3110light breeze

Sunrise & sunset in December

DaylightNight

Daylight runs from about 10 h 18 min at the start of December to 10 h 12 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 6 minutes over December. Sunrise moves from 7:03 AM to 7:19 AM, and sunset from 5:22 PM to 5:33 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
110.37:035:22
210.37:035:22
310.37:045:22
410.37:055:22
510.37:065:23
610.37:065:23
710.37:075:23
810.37:085:23
910.27:085:23
1010.27:095:23
1110.27:105:24
1210.27:105:24
1310.27:115:24
1410.27:125:24
1510.27:125:25
1610.27:135:25
1710.27:135:25
1810.27:145:26
1910.27:145:26
2010.27:155:27
2110.27:155:27
2210.27:165:28
2310.27:165:28
2410.27:175:29
2510.27:175:29
2610.27:185:30
2710.27:185:30
2810.27:185:31
2910.27:195:31
3010.27:195:32
3110.27:195:33

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 3 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 3 kWh/m² to a high of 6.37 kWh/m² in May across the year — December's 3 kWh/m² sits near the bottom.

01234151015202531
Solar energy (kWh/m²)Level
13.1Moderate
23.1Moderate
33.1Moderate
43.1Moderate
53.1Moderate
63.1Moderate
73.0Moderate
83.0Moderate
93.0Moderate
103.0Moderate
113.0Moderate
123.0Moderate
133.0Moderate
143.0Moderate
153.0Moderate
163.0Moderate
173.0Moderate
183.0Moderate
193.0Moderate
203.0Moderate
213.0Moderate
223.0Moderate
233.0Moderate
243.0Moderate
253.0Moderate
263.0Moderate
273.0Moderate
283.0Moderate
293.0Moderate
303.0Moderate
313.0Moderate
Planning a trip in December

Hazard calendar for Merritt Island

In seasonPeak

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

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

Merritt Island's rainy season runs June–October, when most of the year's rain falls.

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

Is December a good time to visit Merritt Island?

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

7.1
Sightseeing
4th-best month of the year
4.7
Beach & pool
10th-best month of the year

December is one of the better times to visit Merritt Island for general sightseeing.

What to pack for Merritt Island in December

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

In December, Merritt Island sees daytime highs around 71°F and nights near 62°F. Little to plan around — just the basics. About 7 days see rain.

Sea temperature near Merritt Island in December

The nearest coast averages about 71°F in December — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 19 mi away) is warmest in September at about 82°F and coldest in February near 67°F.

It's comfortable for a long swim from Mar 2 to Jan 31 — about 11 months when the water holds above 68°F.

65°70°75°80°85°JanFebMarAprMayJunJulAugSepOctNovDeccoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°F)Comfort
Jan69Refreshing
Feb67Cool
Mar69Refreshing
Apr72Refreshing
May76Warm
Jun80Warm
Jul81Warm
Aug82Warm
Sep82Tropical
Oct80Warm
Nov74Refreshing
Dec71Refreshing

UV index in Merritt Island in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 4 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Merritt Island peaks around July 16 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 19 at about 4 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecHighVery highExtremeVery highHighModerateJul 16UV 11Dec 19UV 4
UV index (midday)Level
Jan5Moderate
Feb6High
Mar8Very high
Apr8Very high
May9Very high
Jun10Extreme
Jul11Extreme
Aug10Extreme
Sep9Very high
Oct7High
Nov5High
Dec4Moderate

Air quality in Merritt Island in December

GoodModeratePoorUnhealthyVery unhealthy

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

Air quality in Merritt Island is worst in July — around 19 µg/m³ PM2.5 (moderate), about 2.7× the cleanest month (December, 7 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1019 µg/m³Dec 137 µg/m³
PM2.5 (µg/m³)Level
Jan9Good
Feb11Good
Mar15Moderate
Apr13Moderate
May13Moderate
Jun19Moderate
Jul19Moderate
Aug16Moderate
Sep11Good
Oct9Good
Nov8Good
Dec7Good
Location & terrain

Where is Merritt Island?

Merritt Island sits at 28.4°N, 80.7°W, 3 ft above sea level, in United States. The nearest listed city is Rockledge, 2.5 mi away.

Topography around Merritt Island

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

Within 2 miles, the terrain around Merritt Island has only modest variations in elevation — a maximum elevation change of 39 ft around an average of 7 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 157 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 246 ft.

The land around Merritt Island is covered by water (42%) and artificial surfaces (30%) within 2 miles, water (46%) and trees (25%) within 10 miles, and water (39%) and trees (33%) within 50 miles.

2 miles
39 ft
10 miles
157 ft
50 miles
246 ft
treesgrasslandartificial surfaceswaterwetland
December weather nearby: Rockledge 2.5 mi · Cocoa 3.7 mi · Titusville 19 mi · Melbourne 20 mi · West Melbourne 20 mi · Palm Bay 23 mi · Alafaya 35 mi · Saint Cloud 37 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 Merritt Island (28.359°, -80.69°, elevation 3 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). Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. 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).