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To those who know their local frost dates...

Posted by farmerjude (My Page) on
Tue, Jul 14, 09 at 11:43

I have just finished up a web application for looking up your local frost dates based on the National Climatic Data Center's freeze/frost data. I have checked out everything for my area and it looks good to me.

To those of you who generally know the frost dates for your area, would you give my "Frost Date Finder" a go and see if it checks out for where you are?

Here's the link:

Thanks so much for your help!


Here is a link that might be useful: Moon Garden Calendar - Frost Date Finder

Follow-Up Postings:

RE: To those who know their local frost dates...

Thanks for taking the time to interpret the NOAA data. On your website I was able to type in my zipcode and get the planting data for the nearest NOAA weather stations. And I found it very useful that you included the elevation above sea level of those nearest weather stations - that allows me to make a more accurate estimate for my own location.

However, I think it would help those of us who might consult your website to understand what you mean by some of the terms you use. At present you don't have a FAQ, or other source of explanation. For example, for any particular NOAA weather station you show a "Sow After" date. My guess -- after cross-checking the NOAA data - is that by "sow after" you mean "there's a 90% probability that the temperature will not drop below 36F after this date." I think it's helpful to understand that's what you mean.

Similarly, it would also help if you explained what you mean by your terms "Early Harvest", "Late Harvest", etc.

RE: To those who know their local frost dates...

Brilliant feedback - exactly what I was hoping for. I do have plans to add an 'About This Page' widget to the right-hand side of the page that will act as an on-page F.A.Q. You will be able to click a question/topic and that will expand the explanation below. I have been debating the priority of that feature, so this lets me know where I should be with that.

I also need to make clear that there is a settings form that allows you to tweak the results by changing the temperature threshold and changing the probabilities. There was only a small icon to display the form, so I ditched that and added a big 'Advanced Settings' link below the submit button. This explains a lot of what sent you to the NOAA site. Of course, the on-page FAQ will make everything much clearer.

Otherwise, did the data look accurate for your area?

RE: To those who know their local frost dates...

farmerjude- I guess I don't know how to relate to a single date for sowing. Here are some dates when I have done sowing in my area, rated April 28 with a dot on your page-

Peas March 15- April 15
Fava beans March 15- April 15
Cold tolerant lettuce, cole, etc perhaps April 28 would be a good date, though they could be sowed earlier
Cold tolerant beans April 15
Setting out tomatoes under tunnels April 1-7
Setting out tomatoes without protection May 15
Beans May 15
Squash, cucumbers sowed June 15
or under tunnels set out May 15

Midsummer sowing of cole crops July 15
Fall peas?

So, I'm wondering how your page could relate more to varying cold tolerance of various crops, and to growing them under cover as well as in the open.


RE: To those who know their local frost dates...

Yes, the data did look accurate for this area. Some garden plots 5 miles from mine are a thousand feet higher in elevation, and therefore have different weather, but I don't know how you can correct for that since we don't have any nearby NOAA stations at 1200 feet elevation.

RE: To those who know their local frost dates...

i tried my old zip of 94110, and it returned what is essentially an error.

of course, if you are somewhere free of frost, why would you check your frost dates!

my new zip of 97217 seemed pretty accurate, but same concerns as above. all plants are different!

RE: To those who know their local frost dates...

Maybe instead of 'Sow After' it should say 'Last Spring Frost'. The idea behind this date is knowing when to sow - before or after this date. Your dates are a great example of this. If someone didn't already have the knowledge you do, they might check the back of a seed pack and see something like, "sow indoors 2-3 weeks before the last spring frost." If they were in your area, they would then be able to translate this into April 7-15.

The broader picture here is how this date applies to the personal Moon Garden Calendar that will hopefully be ready by February. You would enter this date in your calendar settings, and based on this date, your calendar is populated with the ideal dates to sow indoors, transplant, sow outdoors, harvest, etc. Thanks for mentioning cold frames. I hadn't thought of this. So, maybe if you added tomatoes to your calendar would would have the option to show dates on your calendar for sowing in cold frames. That's good stuff.

The idea behind the early and late harvest dates also has to do with the Moon Calendar. You would want to sow crops that are harvested once (like pumpkins) based on the early harvest date. This is so that the chance of a frost before you are ready to harvest is minimal. However, for some veggies you will harvest continually up until the fall frost (okra?). The calendar would show the best days to harvest up until the 'Late Harvest' date for those plants.

What do you guys think of 'Early Fall Frost' and 'Late Fall Frost' instead of '...Harvest'? Seems like that is more applicable out of context of the rest of the site.

Sounds like I need the caveat, "Use this data as a general guide, but call your local Cooperative Extension office for dates specific to your location." I should also make a mention in the Page FAQ about micro-climates.

I see what you mean about returning an error. I will update the results to say "Frost Free Location" instead of defaulting to Jan 1 - Dec 31. Thanks!

Thanks so much to you guys for all the great feedback.


RE: To those who know their local frost dates...

I just found your frost date finder and find it super helpful !! I have one suggestion ... you have a little block for zip code info and a block for weather station info. I suggest a block showing the advanced settings that are chosen and also keep the link you can click on to change those settings. That way we don't have to click on the link to see what settings we have chosen. Hope this makes sense ?

RE: To those who know their local frost dates...

I just tried it for three different zip codes I have gardened in and it checks out fine! I like that the map shows where the weather stations are so you can judge how appropriate that one is to your microclimate.

RE: To those who know their local frost dates...

Thanks so much for checking it out and leaving feedback.

That is a great suggestion to see the advanced settings in the page without having to open the settings panel to be reminded, or even to know what the settings are to begin with. I simply took what was in the panel and put it right on the page under the weather station info.

Thank you!

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