september average temperatures honolulu
Days of Hot Weather in Honolulu. Over half the days from December to March in Honolulu have temperatures reaching at least 80 degrees Fahrenheit. Most nights then cool down to below 70, but no less than 50 degrees. Indeed only six nights a year on average have a low temperature cooler than 60. From May to October in Honolulu, daytime highs are consistently above 79 Â°F, and occasionally get into the 90s. Ninety-degree weather is mostly likely to happen in August and September.