African Queen · Photo: Elmschrat · CC BY-SA 3.0Key Largo sits near the top of U.S. towns for mild winters
The warmest part of a July day comes in at 89° on average. Seasons differ by 27°, from the coldest nights to the warmest afternoons. By precipitation alone, it ranks wetter than 88% of U.S. towns. From November to April, highs of 75–82° make it easy to spend the day outdoors.
A year in Key Largo at a glance
Each month’s typical high and low, and what it brings.
What stands out about Key Largo’s climate
Compared with towns across the U.S., with Key Largo’s place in Florida beside it.
What a year in Key Largo feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
Frost is rare
Frost and day counts come from NOAA’s station at John Pennekamp Sp, FL, 6 miles from the town’s center, at about the same height.
The 2023 USDA map puts Key Largo’s center in zone 11a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 44°. Plant labels use the zone; frost dates tell you when to plant.
90° days by month
Average days at 90° or more
About 52 inches of rain a year
September is the wettest month and December the driest. Rain falls on about 96 days a year. Snow is rare: about 0.0" in a normal year at Tavernier, FL, so most winters see none.
Rain + melted snow by month
Inches of water
Heating and cooling a home in Key Largo
2% of the work is heating, so air conditioning is the bigger bill. No month averages under 55°.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at John Pennekamp Sp, FL.
Living with Key Largo’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
Zone 11a. Frost almost never comes, so tender plants can often stay out through winter.
Months with highs of 62–84° and lows of 40° or more: January, February, March, April, November and December. 2.5 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Key Largo from natural hazards, hurricanes are the largest share (67%); heat waves, cold waves, winter storms and ice storms together are 1%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Key Largo and its neighbors
Every town next door is within a degree of Key Largo in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Key Largo’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| Key Largo, FL | 62° | 89° | 52" | 0.0" |
| Heeia, HI | 66° | 84° | 51" | 0.0" |
| Galveston, TX | 48° | 89° | 52" | 0.1" |
| Galliano, LA | 46° | 90° | 63" | 0.0" |
| St. Simons, GA | 43° | 91° | 49" | 0.0" |
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value. Snow and frost-free days come from the nearest weather station, so neighbors often share them.
Warmer than it used to be
The last 30 years in Key Largo averaged 2.0° warmer than the 1900s. The biggest change is in December (+2.8°).
A bigger shift than in 89% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How Key Largo compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Key Largo’s place among Florida’s.
Key Largo weather by month
Highs, lows and precipitation from NOAA’s grid at Key Largo’s center; snow, wet days and snow on the ground from Tavernier, FL. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 75° | 62° | 2.0" | 0.0" | 6 | 0 | 63° – 74° |
| February | 77° | 64° | 2.0" | 0.0" | 4 | 0 | 64° – 76° |
| March | 79° | 66° | 2.0" | 0.0" | 5 | 0 | 67° – 78° |
| April | 82° | 70° | 2.7" | 0.0" | 5 | 0 | 73° – 81° |
| May | 85° | 74° | 4.3" | 0.0" | 6 | 0 | 76° – 82° |
| June | 87° | 77° | 7.3" | 0.0" | 11 | 0 | 80° – 85° |
| July | 89° | 78° | 5.0" | 0.0" | 9 | 0 | 82° – 85° |
| August | 89° | 78° | 6.8" | 0.0" | 12 | 0 | 82° – 85° |
| September | 88° | 77° | 8.6" | 0.0" | 13 | 0 | 81° – 84° |
| October | 85° | 75° | 6.0" | 0.0" | 12 | 0 | 78° – 83° |
| November | 81° | 70° | 2.9" | 0.0" | 6 | 0 | 71° – 80° |
| December | 77° | 65° | 1.9" | 0.0" | 6 | 0 | 62° – 79° |
| Year | 83° | 71° | 51.6" | 0.0" | 96 | 0 |
How much a month can swing
A normal is an average. December swings the most: from 1991 to 2020 its average ranged from 62° to 79°. September is the most reliable, staying within 3°.
Where Key Largo’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at Key Largo’s center.
- Snow: Tavernier, FL.
- Frost, freezing nights, 90° and 100° days, heating and cooling: John Pennekamp Sp, FL, 6 miles from the town’s center, at about the same height; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about Key Largo’s climate
What is the weather like in Key Largo?
A typical July afternoon reaches 89°, a January night drops to 62°, and snow is almost unheard of. Milder January nights than all but 75 U.S. towns; hotter July afternoons than 73% of U.S. towns.
How cold does it get in Key Largo in winter?
January nights average 62°. A night at 32° or below comes in only some winters (0.0 a year on average). In the coldest January of the last 30 years the month averaged 63°.
How much snow does Key Largo get?
About 0.0 inches in a normal winter at Tavernier, FL, so most winters see none.
How hot does it get in Key Largo?
July, with a typical high of 89° and a low of 78°. About 47 days a year reach 90° (John Pennekamp Sp, FL).
When is the first and last frost in Key Largo?
Most years have no frost at all: a 32° night comes in about 0% of winters at John Pennekamp Sp, FL, usually in December or January.
What growing zone is Key Largo in?
Zone 11a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 44°.
What is the best time of year to visit Key Largo?
By one simple rule (highs of 62–84° and lows of 40° or more), January, February, March, April, November and December. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Key Largo getting warmer?
Yes: 1991–2020 averaged 2.0° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 89% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Key Largo.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.