I'm working on a small project and am trying to find a way to get the very extended hour-by-hour forecast for a location. Most services (Darksky, etc.) seem to offer 7-day extended hourly forecasts, but I'm not able to find anything beyond that.
Does anyone have suggestions?
The trouble is, any skill above climatology beyond about 5-7 days is very very low.
So sites could offer such forecasts, but they wouldn't be worth much of anything.
The main thing they could offer that has any use that is an indication of what typically happened in previous years (i.e. climatology)... but unfortunately I don't know any site that offers such on an hourly basis. We could use more of that! Still, if you're familiar with the area you're looking up for, you're probably fairly used to the typical weather for a given time of year.
There has been some small skill at making blurrier longer range forecasts... basically estimating either within a large range (such as hurricane forecasts) or (more often) giving probabilities of whether the weather will be above or below that climatological expectations.
For more about the very limited skill of week 2 forecasts, see this answer.
But such long-range forecasts don't have nearly the precision to offer hourly forecasts to be of any legitimate use. It'd be like saying it'll take you 46 minutes and 7 seconds to get to work two weeks from Thursday... entirely misleading specificity.
So basically if you're eagerly planning for a trip in 10 days or a wedding in a month or two, you're much better off staying far away from such novelty longrange forecasts until the event gets much closer. Until then, all you can really figure on is what's typical for the given time of year.
Weather Underground and Intellicast provide ten day forecasts in a beautiful (to a nerdy engineer) graphical format, in hourly increments. The skill in the last two to five days of those extended forecasts is suspect.
Accuweather Premium claims 15 days of hourly forecasts.
This may be just as good though.
ECMWF (European Centre for Medium-Range Weather Forecasts) provides global forecast to member organizations and probably there is a way to obtain their hourly forecast up to 15 days. They provide average fields to the public, but the hourly data is not available that way. You can contact them directly and ask them about availability.
No.
The atmosphere is too chaotic for hourly forecasts at time scales beyond several days to be useful.
The best solution I've found so far is to use Dark Sky's Time Machine. You can request the forecast for any number of days in the future, and beyond 10 days, the API simply returns historical data.
