So what is the best solution? Just like in Los Vegas. ‘ Pay your money and take your chances!’ But your odds are way better here than in Los Vegas because you won’t lose any money if your bet does not pay off. If a tour is cancelled because of inclement weather, you will be notified at the determination time of the cancellation and you will be refunded the amount you paid in full. Now you might argue that you may have not lost any money but you did lose a day out of your vacation, and this might be true. Life being life, the best way to protect yourself from this loss of time would be to play the best odds. How do you know the best odds? You compare the timing of your anticipated activity to the the data regarding this date in past years. It is good to know your chances for good weather. If in the event, it does not work out in your favor, at least you did all you could to play the odds right.
So here is a look at the general weather conditions throughout the year that could effect your Oahu tours. These are general guidelines that should help you, but even if they don’t, you will know that you did your best and that in itself will diminish your disappointment.
So, this is the biggest generalization regarding Oahu weather: ‘It rains in the winter and its sunny in the summer’. Sounds just like your weather at home, right! Well it is. If you live in the northern hemisphere, whether in the US. Canada, Europe or elsewhere that is going to be a standardized generalization. But of course we know that each area of the planet has its basic micro-climates which make them somewhat unique. And this is true of Oahu as well. So here is the month to month breakdown at sea level in Honolulu which is the area that most visitors will stay when visiting Oahu:
Winter Season runs roughly from November through March. This will be your most likely time for inclement weather conditions. Depending upon the year you could expect between 4 and 5 rainy days each month. The temperatures will be very pleasant ranging from a high of between 80 and 84 degrees and a low of between 66 and 71 degrees. Your average rainfall will range between 2 and 3 inches per month but keep in mind that although it will actually truly rain in earnest the number of days mentioned above there will be some form of light rain or mist at some point of the day between 11 and 14 days of every month. This light precipitation will likely be just refreshing at worst and will actually present the opportunity for beautiful rainbows and such and in most circumstances will not effect your daily activities and tours whatsoever.
Summer Season will run between April and October. This is the season you will have the least likelihood of rain and also the highest daily temperatures, which will still remain in the temperate zone (Hawaii has only had one day that reached 100 degrees in the last 100 years and that was on the Big Island in 1931). The daily high temperature will run between 83 and 89 degrees and the daily low temperature will run between 69 and 75 degrees). The average monthly rainfall will vary between .5 and 1.5 inches and the number of days when there will be some precipitation will be between 11 and 13 days.
Well that is the big picture but there are variations, the biggest one being where on the island you are. As mentioned above, the stats we mentioned were for the Honolulu area but Oahu, being and island, climatic conditions change as you travel from area to area. The prevailing winds are called ‘Trade Winds’ and they blow between 250 and 300 days a year from the northeast buffeting the northern coastlines of Oahu. With these winds comes more rain and limited sunshine on some days. On Oahu this area is referred to as the ‘country’ and it is very beautiful and not to be missed.
The other climatic condition that can affect your activities and tours can happen due to storms in hurricane season. These happen infrequently but can have a definite effect when they occur. Although hurricane season in Hawaii runs between June and November the most likely months for one to occur are going to September and the months surrounding it. Each year a series of hurricanes launch off the coast of Mexico and churn like bowling balls toward the Hawaiian Islands. Most will veer off to the north before getting within proximity of the islands and many will stay south and just pass us by. Very occasionally they do get close enough to effect the overall island weather but in recent memory Oahu has never experienced a direct hit. Kauai has been more unlucky. Usually if one gets close there will be many precautions taken and most activities and tours will be cancelled until it has passed. I doubt that this should be a reason to avoid visiting Oahu in September but in all fairness it is a part of the complete weather pattern that exists here.
In the big scope of things, these are weather considerations you might want to keep in mind, but generally speaking it is probably in your best interest to just come to visit Oahu at the time that best fits into your schedule. The temperature here is temperate and actually some of the best that could ever be found on the planet.