Weather — Sebastian, Florida

The National Weather Service office in Melbourne issues the official forecast, watches and warnings for Sebastian and the rest of Indian River County.

The official forecast for Sebastian comes from the National Weather Service forecast office in Melbourne, known as NWS Melbourne. According to the office's profile of its own operations, NWS Melbourne is responsible for 10 counties in east central Florida, in addition to 6 Atlantic marine zones, and its marine area runs from Flagler Beach to Jupiter Inlet out to 60 nautical miles. That footprint puts the city, the Indian River Lagoon shoreline and the ocean off Sebastian Inlet under one office. Meteorologists there work a 24-hour rotating schedule and issue the severe thunderstorm and tornado warnings for Indian River County, along with the aviation, marine and fire weather forecasts used around Sebastian.

The arrangement dates to the late 1980s. The NWS Melbourne office history records that Melbourne became the first field office completed under the national Weather Service modernization in July 1989, and that forecast and warning operations began for Brevard, Indian River, Lake, Orange, Osceola and Seminole Counties in October 1989. Sebastian has had a Melbourne-issued forecast for 37 years as of 2026.

Within that system, Sebastian falls in the forecast zone the Weather Service calls Coastal Indian River, zone FLZ154. A point forecast requested for central Sebastian on forecast.weather.gov on October 10, 2026 named Melbourne as the local forecast office, labeled the point 2 Miles SE Roseland FL, and linked to the Zone Area Forecast for Coastal Indian River. The Coastal Indian River zone forecast gives one text forecast for that stretch of Indian River County, with highs, rain chances, winds and heat index values, while the point forecast is computed for the chosen spot.

Live conditions for Sebastian are measured at Sebastian Municipal Airport (KX26) on the mainland and at station SIPF1 on the Sebastian Inlet north jetty.

The nearest official surface observation is at Sebastian Municipal Airport, station KX26. The Sebastian point forecast lists the airport at latitude 27.81 N, longitude 80.5 W and an elevation of 22 feet, and shows its latest reading at the top of the page. At 3:15 p.m. on October 10, 2026, KX26 reported 88 degrees, 79 percent humidity, a southeast wind of 15 mph gusting to 21, and a heat index of 106 degrees, with a thunderstorm in the vicinity.

On the barrier island, the National Data Buoy Center carries station SIPF1, a weather station at the Sebastian Inlet State Park north jetty that is owned and maintained by the Florida Institute of Technology. SIPF1 reports wind speed, barometric pressure and air temperature from a site 10.06 meters above mean sea level, and the buoy center notes an associated wave and current site about 0.3 nautical miles north northwest of the jetty station.

For long-term records the Weather Service uses the Vero Beach airport station rather than Sebastian. The NWS Melbourne climate page publishes daily, monthly and annual climate reports for Vero Beach alongside Melbourne, Fort Pierce and Orlando, and states that the National Centers for Environmental Information is the source for official and certified data. Radar coverage over Sebastian comes from the Melbourne WSR-88D (station KMLB). The office history states that this radar began operational use in October 1991 as the second WSR-88D in the nation and the first in a sub-tropical, maritime climate, and that in August 1992 it became the first operational NEXRAD to track a hurricane, Andrew.

Normal Sebastian weather, measured at the Vero Beach airport station, runs from a January high of 73.3 degrees to an August high of 90.6, with 53.25 inches of rain a year.

The National Centers for Environmental Information computes the official 1991 to 2020 climate normals for the Vero Beach airport station (USW00012843) in Indian River County, the station NWS Melbourne uses for its county climate reports. The annual normals put the mean temperature at 73.6 degrees, the average daily high at 82.7 and the average daily low at 64.5, with 53.25 inches of precipitation in a normal year. The same table counts 72.0 days a year with a high of 90 degrees or warmer and 1.6 nights at or below freezing.

The monthly normals trace the shape of the year at Vero Beach. January is the coolest month, with a normal high of 73.3 degrees, a low of 52.2 and 2.74 inches of rain. February is the driest month at 2.20 inches. July averages a high of 90.5 over a low of 73.3, and August, at 90.6 over 73.6 with 7.35 inches, is both the warmest and the wettest month. September follows with 7.04 inches and a mean of 80.9 degrees, October still averages 5.33 inches, and November drops to 2.91.

Added up, May through October account for about 36.4 of the 53.25 inches at Vero Beach, roughly two thirds of the annual total, the wet season for Sebastian, the Sebastian River basin and the rest of Indian River County. Each monthly climate report NWS Melbourne issues for Vero Beach compares the observed month against this 1991 to 2020 normal period, so the normals are the baseline for every departure figure published for Indian River County.

The record high for the Vero Beach station nearest Sebastian is 102 degrees, set on June 22, 2009, and the record low is 21 degrees, set on January 22, 1985.

The Vero Beach climate summary for 2025, issued by NWS Melbourne on January 1, 2026, lists a record high of 102 degrees on June 22, 2009 and a record low of 21 degrees on January 22, 1985, within a climate record period that runs from 1942 to 2025. Those are the extremes of record for the Indian River County climate station nearest Sebastian.

The same report shows how 2025 compared with normal at Vero Beach. The year averaged 74.0 degrees against a normal of 73.6, and it logged 95 days at 90 degrees or warmer against a normal of 72.0. The lowest reading of 2025 was 34 degrees on December 31, the highest gust was 54 mph on July 10, and the report counted 87 days with thunderstorms and 169 days with fog.

The latest monthly summary, for September 2026, recorded an average high of 88.7 degrees at Vero Beach against a normal of 88.4, a greatest 24-hour rainfall of 2.28 inches on September 6 and 7, and a highest gust of 48 mph on September 7. Month by month, these reports are the official measure of whether a Sebastian summer ran hotter or wetter than usual.

NWS Melbourne warns Sebastian most often about lightning storms, rip currents, heat, flooding rain, small craft conditions and tropical systems.

The hazard map on the NWS Melbourne home page lists the warning products the office issues along its coast, among them flood warnings, coastal flood warnings and advisories, storm surge watches, small craft advisories and rip current statements. On October 10, 2026, the Sebastian point forecast carried a Rip Current Statement in effect until 1 a.m. on October 11, covering the beaches of the Coastal Indian River zone around Sebastian Inlet.

Thunderstorms and lightning are the most frequent hazard. The office's Lightning Information Center calls central Florida the Lightning Capital of the United States and states that lightning is responsible for more weather-related deaths in Florida than all other weather hazards combined. At Vero Beach, the 2025 annual report counted 87 thunderstorm days, close to one day in four for the station nearest Sebastian.

Heat is the other routine summer hazard. On October 10, 2026, the Coastal Indian River zone forecast called for heat index values up to 104 degrees, and the Sebastian Municipal Airport reading that afternoon put the heat index at 106. The 1991 to 2020 normals count 72 days a year of 90 degrees or more at Vero Beach, and 2025 ran 23 days above that figure, so heat index readings past 100 are a regular feature of a Sebastian summer and early fall rather than an exception.

Seasonal outlooks come from the same office. On October 10, 2026, the NWS Melbourne home page carried an outlook titled Increased Potential for Well Above Normal Rainfall and Severe Weather This Upcoming Dry Season, covering November 2026 through April 2027, for Indian River County and the rest of east central Florida. Tropical systems are tracked from Melbourne as well; the office profile lists Erin, Frances, Jeanne, Wilma, Matthew, Irma, Dorian, Ian and Nicole among the hurricanes that affected its warning area, which includes Sebastian.

Weather Service warnings reach Sebastian through NOAA Weather Radio transmitters WWF69 and WXJ70, Wireless Emergency Alerts on phones, and city and county storm pages.

NOAA Weather Radio is the Weather Service's own broadcast. According to the NWS Melbourne transmitter page, the office programs four transmitters, and two of them alert Indian River County: WWF69 in Fort Pierce on 162.425 MHz and WXJ70 in Melbourne on 162.550 MHz. Sebastian sits between the two sites. Weekly tests of the alerting tones run every Wednesday between 11 a.m. and noon and move to the next day when active weather is under way.

The same page notes that Wireless Emergency Alerts on phones are activated only for the most life-threatening weather hazards, such as hurricanes, tornadoes, destructive severe thunderstorms, considerable or catastrophic flash flooding and tsunamis, while a weather radio broadcasts warnings, watches, forecasts and other hazard information 24 hours a day. The office states that everyone should have more than one way to receive weather alerts, advice that applies to every household in Sebastian.

The City of Sebastian points residents to the same federal sources. Its Tropical Weather Information page links the National Hurricane Center and gives the Indian River County Emergency Services number, 772-226-3900, for questions about NOAA Weather Radios.