Seasonal Weather Patterns in Melbourne, Florida

Melbourne has two working seasons, a wet season that starts around a median May 28 and a dry season that starts around a median Oct. 17, by the National Weather Service count for Melbourne since 1950 (NWS Melbourne, wet and dry season onset).

The cool weather lags the dry air by a few days and then by weeks. For Melbourne, NWS Melbourne puts the median first reading below 60 degrees on Oct. 22 and the first below 50 degrees on Nov. 10. Each date is a median, so half of Melbourne years arrive earlier and half later (NWS Melbourne).

The switch is set by moisture, not by the calendar. The NWS Melbourne Florida Rain Machine page says the dry season begins when a cold front passes and brings drier air, the first day many people can turn off the air conditioning and open the windows, and that in most years this happens by the middle of October (NWS Melbourne, The Florida Rain Machine). On October 18, 2026, Melbourne sat one day past its median dry season start.

At Melbourne International Airport, the 1991 to 2020 normal high runs from 71.8 degrees in January to 89.7 in July, and normal rain totals 50.79 inches a year (ACIS normal highs; ACIS annual normal).

The highs come from the ACIS normal high series, the lows from the normal low series and the rain from the monthly normal precipitation series for the same Melbourne station (ACIS highs; ACIS lows; ACIS rain). In the ACIS web service, normal=91 selects the NCEI 1991 to 2020 normal (ACIS documentation).

Read across the Melbourne rows and the shape is lopsided. Lows stay at 73.1 degrees or warmer from June through September. The rain column jumps from 3.53 inches in May to 7.10 in June, and September is the wettest month at 7.63 inches, while February is the driest at 1.98 (ACIS normal rain, Melbourne airport). July, at 6.50 inches, comes in below both June and August, a small mid-summer dip in the Melbourne normals.

Melbourne summer storms come from the daily collision of the Atlantic and Gulf sea breezes, whose meeting point is steered by the Bermuda high pressure ridge, a pattern NWS Melbourne calls the Florida Rain Machine (NWS Melbourne).

The ridge moves north and south through the summer, and its position controls the low level wind and so decides where the Gulf and Atlantic sea breezes meet each day. Where they meet, widespread storms with frequent lightning and heavy rainfall often follow (NWS Melbourne, The Florida Rain Machine). NWS Melbourne ties both the timing and the distribution of summer showers and lightning storms over east central Florida to that north and south migration of the ridge.

The airport numbers show how much of the year that machine supplies. June through September add up to 27.90 of the 50.79 normal inches at Melbourne International Airport, about 55 percent, and May through October reach 36.29 inches, about 71 percent (ACIS monthly normals; ACIS annual normal).

Heat comes with it. The normal count of days at or above 90 degrees at KMLB is 62.8 a year, and 2025 logged 64. The same 2025 Melbourne report counted 93 days with thunderstorms and 136 days with fog (NWS Melbourne 2025 climate report for KMLB).

Melbourne cools off from late October, when the median first reading below 60 degrees arrives on Oct. 22, and January is the coolest month at the airport with a normal low of 51.7 and a normal high of 71.8 (NWS Melbourne; ACIS normal lows).

Winter at KMLB stays mild in the normals. The normal lows stay in the 50s from December through February at 55.6, 51.7 and 54.0 degrees (ACIS normal lows, Melbourne airport), and the normal count of heating degree days is only 485 a year against 3446 cooling degree days (NWS Melbourne 2025 report). Cold snaps still happen. The Melbourne record low is 19 degrees on January 20, 1977, and the coldest reading of 2025 was 35 degrees on December 31 (NWS Melbourne, KMLB).

The coming Melbourne winter may be wetter than the table suggests. The NWS Melbourne dry season forecast issued in September 2026 says El Nino conditions have developed, that a very strong El Nino is forecast, and that central Florida has a higher probability of wetter than normal conditions from November 2026 to April 2027, with more seasonal storminess and potential for severe weather, while temperatures lean toward normal (NWS Melbourne Dry Season Forecast). The Melbourne weather hub follows that outlook as it is updated.

The Melbourne wet season and hurricane season largely overlap: the city lists hurricane season as June 1 through November 30, and the Atlantic peak of September 10 lands in the wettest month at the Melbourne airport (City of Melbourne; NHC).

The National Hurricane Center says most Atlantic activity falls between mid-August and mid-October (NHC climatology), the same weeks when Melbourne International Airport normally collects 6.67 inches in August, 7.63 in September and 4.86 in October (ACIS normal rain). The City of Melbourne says everyone east of the Indian River Lagoon is on a barrier island and in the mandatory evacuation zone, naming Satellite Beach, Indian Harbour Beach, Indialantic and Melbourne Beach among those communities (City of Melbourne, Hurricane Preparation). The Melbourne hurricane season guide covers preparation.

The seasons also set the Melbourne watering calendar. The city schedule follows St. Johns River Water Management District water conservation rules and city ordinance: during daylight saving time, from the second Sunday in March to the first Sunday in November, homes with odd addresses may water on Wednesdays and Saturdays and even addresses on Thursdays and Sundays; during Eastern Standard Time each drops to one day, Saturday for odd and Sunday for even. Watering is never allowed between 10 a.m. and 4 p.m. (City of Melbourne, Irrigation Schedule).

That puts the next Melbourne change on Sunday, November 1, 2026, the first Sunday in November, about two weeks after the median Oct. 17 start of the dry season (City of Melbourne; NWS Melbourne). Lawns get fewer watering days just as the normal rain falls from 4.86 inches in October to 2.55 in November (ACIS normal rain).

Recent Melbourne readings have run warmer than the 1991 to 2020 normals: the 2025 mean at KMLB was 73.9 degrees against a normal 73.1, and September 2026 averaged 81.0 against 80.6 (NWS Melbourne 2025 report; September 2026 report).

The 2025 figures come from the annual Melbourne report issued January 1, 2026 (NWS Melbourne CLA), and the September 2026 figures from the monthly report corrected October 10, 2026 (NWS Melbourne CLM). Through September 2026, Melbourne cooling degree days for the year ran 459 above normal, about 16 percent.

September 2026 itself was typical in shape for Melbourne. The average maximum of 87.6 matched normal exactly, the hottest day reached 96 on September 5, the greatest one day rain was 1.48 inches on September 7, and the month logged 14 thunderstorm days with an average humidity of 78 percent (NWS Melbourne, September 2026 KMLB report). Melbourne extremes in the 2025 report also show the range of a single year: a high of 96 on May 21, a week before the median wet season start, and a top gust of 61 mph on March 31 (NWS Melbourne 2025 report).

Last verified: October 18, 2026, against the ACIS 1991 to 2020 normals for Melbourne International Airport and the NWS Melbourne season study, Rain Machine page, KMLB climate reports and dry season forecast.