Hurricanes and Tornadoes That Hit Guayanilla, PR

The nearest NOAA station with 1991–2020 climate normals is Adjuntas Substn, PR RQ, 9 miles north of Guayanilla at 1,830 feet. August is the warmest, with an average high of 85°F and low of 64°F; February is the coolest, at 80°F and 56°F. September is the wettest at 12.9 inches of precipitation on average and January and February the driest at 2.6 inches; the year adds up to 80.2 inches over 116 days with at least a tenth of an inch. June to November, the hurricane season months, bring 62% of the year's precipitation (49.9 of 80.2 inches); the other six months are drier. September has brought the most of the 51 tropical systems that passed within 75 miles (24); a normal September there has highs of 85°F and 12.9 inches of precipitation. Highs reach 90°F on about 1 days a year. A night below freezing comes less than once a year on average. That 80.2 inches is more than at 19 of the 21 Puerto Rico stations used on this site (90%). Guanica, 8 miles southwest, has its own station (Magueyes Is, PR RQ): 42.6 inches a year, 37.6 less than here, and an August average high of 91°F against 85°F.

Water temperature at the NOAA tide station Magueyes Island, PR, 17 miles west, averaged 88°F in September and 81°F in February over 2021–2025. Sea level at the Magueyes Island tide gauge, 17 miles from Guayanilla, has risen 0.81 ± 0.06 inches per decade from 1955 to 2025, NOAA's linear trend; at that pace it is 8.1 inches in a hundred years. That is faster than at 41 of the 144 U.S. gauges with a NOAA trend.

Since 1996, the National Weather Service has logged 136 flood, rain, thunderstorm wind and lightning events that began within 10 miles of Guayanilla: 68 flash floods, 42 floods, 14 thunderstorm wind reports, 11 heavy rain events and 1 lightning strike. They killed 4 people and injured 2, and the NWS estimated $1.9 million in property and crop damage. The strongest thunderstorm gust on record here was 60 mph, on November 11, 2024. May has had the most flash floods, 26 of 68. Of the 86 Puerto Rico cities on this site with a flash flood on record, 38 have had fewer than Guayanilla.

Flood insurance policyholders in Guayanilla's ZIP code 00656 have filed 215 claims with the National Flood Insurance Program since 1979, and were paid $1.9 million for buildings and contents, in the dollars of each year. The most came from Flooding in 1982: 41 claims (19% of all) and $194,000, then Hurricane Georges in 1998 with 23 and Hurricanes David & Frederic in 1979 with 22. 60% of the claims carry the name of a storm or flood event; the rest have no event name. Of the 72 Puerto Rico cities on this site with 10 or more claims, 49 have fewer than Guayanilla.