Historical weather data, all-time temperature records, and monthly climate averages for Waipahu, HI. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
April 5th in Waipahu typically lands right in the sweet spot of spring warmth, with an average high of 82° and a low of 68°. This date saw its warmest high just this year — 88° in 2025 — while the coldest it's ever dipped was 61° back in 1966. There's a 1-in-4 chance of catching some rain, but snow has never been part of the picture.
Waipahu's climate is remarkably stable, but it's not without its extremes — the mercury has reached 95° (August 2019) and dropped as low as 52° (January 1969), a 43-degree spread over 85 years of records. The most dramatic day on record was March 5, 1958, when a staggering 15.32 inches of rain fell in a single day.
Waipahu is a year-round warm destination, with average highs ranging from just 80° in early January to 88° at peak summer in late July and August. If you're chasing the warmest weather, aim for July through September; if you prefer slightly cooler and less humid conditions, January through March is your window. Rainfall peaks in mid-to-late December, so the holiday season is when you're most likely to need an umbrella.