Anyone know of a site showing prevailing winds by month

[Calum]

Anyone know of a site where I can look up the prevailing winds in different US states for different months of the year?
Thanks!

[John Nettles]

I use a variety of sources but WeatherSpark gives a LOT of weather data for a given location.  There are general "wind roses" out there which show the wind direction from the various points for a given state.  Some are better than others.

Best, John

[Calum]

Perfect! Thanks very much. So for riding the Pacific Coast in October, it looks like the winds are going to be less reliably north to south than in July, but I'll give it a shot anyway!

[John Nettles]

Way back in 87, I did the PC south to north (part of a USA Perimeter tour).  I had headwinds almost everyday in July in California.  Some days it was ridiculously strong, i.e. I am in my granny gear and I was a 20 something strong stud (now just a middle aged wimpy fart).  Anyway, if you are considering July, head North to South.  Can't advise on October except consider all factors, i.e. are any services closed for the season, how much rain and how many days, less daylight hows to ride in, etc.

Best, John

[Pat Lamb]

There are general "wind roses" out there which show the wind direction from the various points for a given state.  Some are better than others.

I've been going to the NRCS/NWCC site for wind roses for years:
https://www.wcc.nrcs.usda.gov/climate/windrose.html

If there are better sites out there, what are they?  (Old dog might want to learn a new trick.)

[John Nettles]

I've been going to the NRCS/NWCC site for wind roses for years:
https://www.wcc.nrcs.usda.gov/climate/windrose.html

If there are better sites out there, what are they?  (Old dog might want to learn a new trick.)

This is the best one I know of.  I like WeatherSpark as my primary / initial search since it has many more locations and it provides a lot of other information, i.e. I may have good tailwinds but they would be in the rain versus going on another month.  While I am a big proponent of tailwinds, I do want to know what the cons are, if any.

However, as Wind Roses ONLY go, this is my favorite.

[walks.in2.trees]

I like Weather Underground.

The app is great for current conditions and near-future predictions, but the website is way more details including weather history, and, in general the data set includes not just the big weather stations but also crowd-sourced private weather stations which gives them a higher resolution data set to use.

As you can see in my attached screen shots:

on the Wundermap you can clearly see current wind conditions for San Francisco (chosen because the Pacific coast was being discussed) and can also activate numerous other map overlays, including active forest fires, storm tracks, and so on.

You can select weather history by day, week, month, year, or a custom range. I use this to determine what types of gear I might need.

You can clearly see in the wind graph what direction the wind is generally from.

The windroses are graphically prettier, but this graph does the same job and it's just as easy to understand.




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[John Nettles]

Like you said, WeatherUnderground is good for current and/or near forecasts.  However, if you want weather AVERAGES, you have to review numerous years and then determine your "average".

In the example you included, an average is not shown, only the history for a given month, August 2016.  Obviously, not every August is the same so you can not assume that the August 2016 history is an accurate average.  At least in the USA, WeatherSpark uses NOAA's 30-years weather averages.

Again, I agree WeatherUnderground is good for current and/or near term forecasts primarily due to its bazillion stations.  However, I firmly believe WeatherSpark is better for averages.

Best, John

[canalligators]

A terminology clarification: "Weather" is the current conditions and forecast.  "Climate" is the historic record, averages, etc.