Chill Hours

[wd40]

Those of us that have fruit trees are interested in the number of chilling hours our trees have seen during the winter months.

The simple method for this calculation in hours is the number of hours the temperature is below 45F for the duration of fall till spring bloom.

If there is enough interest in chill hours would it be possible and practical to have Cumulus track chilling hours?

Randy

[seabreeze3]

If I might sit on the side, I never knew that about fruit trees or orchard crops. I have berries of varying species. I wonder if the same thing applies?

[steve]

Yes, this is a good suggestion. I've also heard of things called 'cooling days' and 'heating days', which I assume are related, although I haven't looked into them.

[Gordon-Loomberah]

I'm certainly interested in chilling hours for my cherry trees

Cooling and heating days are I think related to house cooling and heating required to keep it comfy indoors...

[Gina]

That provokes some thoughts... Unrelated to Cumulus, but I think it would be interesting to see how long our air conditioning is on for - either heating in the winter (boosting the central heating for the lounge) or cooling in the summer (when we get the odd heatwave). Could also read the CH boiler output temperature to get an idea of the heat input from that source and times the CH is on. Whether this sort of info would be of any interest to anyone outside the household I don't know.

[gemini06720]

Here is what I found about heating degree day and cooling degree day...

"To calculate the heating degree days for a particular day, find the day's average temperature by adding the day's high and low temperatures and dividing by two. If the number is above 65, there are no heating degree days that day. If the number is less than 65, subtract it from 65 to find the number of heating degree days. For example, if the day's high temperature is 60 and the low is 40, the average temperature is 50 degrees. 65 minus 50 is 15 heating degree days."

"Cooling degree days are calculated by subtracting 65 from a day's average temperature. For example, if the day's high is 90°F and the day's low is 70°F, the day's average is 80°F. Eighty minus 65 is 15 cooling degree days. Cooling degree days can be used to compare the current summer to past summers. It can also be used to compare the heat in one part of the country with another."

Both quotes extracted from articles in USA TODAY. There is also this Heating degree day article on Wikipedia.

[wd40]

Yes, this is a good suggestion. I've also heard of things called 'cooling days' and 'heating days', which I assume are related, although I haven't looked into them.

That is great news.

Here is a link to our local agriculture weather data collection system that is about to shut down due to budget short falls. I thought you might find it interesting on what they track.

http://www.griffin.uga.edu/aemn/cgi-bin ... ?site=GABA

Chill hours do crossover to other plants if I remember right.

I have a cherry trees as well. I have an English Morello and a North Star, close cousin of the Morello freshly planted this year. English Morello makes the best Cherry pie. I will post a picture of first apple tree to bloom in another post.

Thank you Steve for considering the chill hour and other ag type weather tracking.

There are more complicated chill hour calculations but I am not sure all the ag people agree with the more complicated methods. In your part of the world, there may be a different method and that would be fine to me as well. I will do a bit of digging.

Randy

[wd40]

This is from the Texas A&M site a noted agriculture site.

"The three most common models are: the number of hours below 45 degrees F model, the number of hours between 32 and 45 degrees F model . . . ."
The third model mentioned is much more complicated and is not as widely accepted as these two.

The second model takes into account a hard winter and cuts off the Chilling Hours below 32F because test have soon temperatures below 32F are too cold and therefore do not count as chilling hours. The third model starts subtracting chill hours if it gets very cold.

The duration of the counting could be simplified by counting say from September 1st to September 1st the following year. Our Southern Hemisphere people would have a different day for sure. A graph would be nice but not necessary.

Randy

[wd40]

Steve, would you like an Enhancement Request on the chill hours?

Randy

[steve]

Steve, would you like an Enhancement Request on the chill hours?

It's best if you do, because I won't be able to do it immediately, and I'll probably forget

[wd40]

Will do. I want to finish my research first. I have ran into a conflict of definition between Chill Hours and Chill Units. As soon as I pin down this question I will post the request.

Randy

[nking]

As a result of reading this topic I came across this site http://www.degreedays.net/ which has a very interesting calculator which uses wunderground data. It's worth a read and if you provide data to WU then it can be very specific for your location.

[Darknstormy]

Hi all, I just looked this up I think its a great idea as I have apple trees... but my question is who's season does cumulus calculate? as I'm in Australia my winter is now

[steve]

You can set it to start on the first of any month. See: https://cumulus.hosiene.co.uk/tracker.php?p=1&t=117

It won't calculate it retrospectively.

[Darknstormy]

Thanks Steve, I must be blind I didn't see you had a Feature tracker