Degree Days

What are degree days?

Growing degree days (DD) are a weather-based indicator for assessing crop and pest development. It is a calculation used by crop producers that measures heat accumulation used to predict plant and pest development rates. Growing degrees are defined as the mean daily temperature (average of daily maximum and minimum temperatures) above a certain threshold base temperature accumulated on a daily basis over a period of time. Daily growing degree day values are added together from the beginning of the season. Degree day totals are also used for comparing the progress of a growing season to the long-term average.

Degree Day Development Table

The codling moth, like all insects, is cold blooded. Meaning, the temperature around it determines how fast it grows and how active it is as an adult moth. We can take advantage of this to predict what life stage the majority of the codling moths population are in. Scientists have developed a model that uses degree–days to predict codling moth development. These predictions are summarized in this table.

Degree day total
(+/- 3-5 DD)		Codling moth stage of development
100Emergence of 1st brood moths from overwintering larvae
150Beginning of 1st brood egg laying
220Start of 1st egg hatch (first brood larvae)
500End of emergence of 1st brood moths
575Start of emergence of 2nd brood moths
650End of 1st brood egg hatch
700Start of 2nd brood egg hatch (2nd brood larvae)
1140End of 2nd brood moth emergence
1160Start of 3rd brood moth emergence
1275End of 2nd brood egg hatch
1300Start of 3rd brood egg hatch

A complete codling moth degree day development table is also available as a PDF – Full Codling Moth Degree Day Development Table.

More information about the codling moth stages of development, see Codling Moth.

Degree Day Tables

The degree day totals in the table below indicate the predicted stage of development of codling moth populations near specific weather stations located around the valley. Growers and advisors can use the values to determine the life stages of the codling moth in their area. This will help determine the proper time to apply ovicidal and larvicidal products to control each of the codling moth generations if needed.

  • 2018 Degree Days - South
    Weather Station Location
    		OsoyoosOliver SouthOliver CentralCawstonKeremeosPenticton AirportSummerland North
    August 13, 20181256118411321226123710331022
    August 10, 2018121911521098119412051001990
    August 8, 201811881125107011591171972961
    August 7, 201811741110105611431155958949
    August 1, 20181092103298010621070883875
    July 30, 20181060100495110271037854849
    July 25, 2018991936884945955784783
    July 23, 2018960907856912922756758
    July 20, 2018923873823877884723730
    July 18, 2018893703795852858703707
    July 16, 2018862815766816824675676
    July 13, 2018818776729722779637630
    July 11, 2018788749704742748612600
    July 9, 2016764728683720725595584
    July 6, 2018729696653685690565558
    July 4, 2018698667625658662538534
    June 29, 2018656628585617621501502
    June 27, 2018642613571603606489483
    June 25, 2018625599558590591477473
    June 22, 2018592567527556555445444
    June 20, 2018568544504534533423421
    June 18, 2018537516476505503392394
    June 15, 2018505482446470469361363
    June 13, 2018490469433459457349353
    June 12, 2018483463427452451345349
    June 8, 2018466444412438434331335
    June 6, 2018448426394418414314320
    June 4, 2018433411381404400303309
    June 1, 2018403384357381378286291
    May 31, 2018394376349373371280284
    May 28, 2018367352328355354265263
    May 25, 2018328316295323320240245
    May 23, 2018305295274298297220224
    May 18, 2018258248232251252183188
    May 16, 2018238228213230234166166
    May 14, 2018216206191204208145144
    May 11, 2018185175161170174120116
    May 10, 2018177167154164168114111
    May 7, 201815714613514114610197
    April 23, 201860564844493025
    April 4, 2018172017161776
    Data from Osoyoos, Penticton and Summerland comes from Environment Canada.
    Data from Oliver south, Oliver north, Cawston, and Keremeos comes from Growers Supply's weather network.

  • 2018 Degree Days - Central
    Weather Station Location
    		West KelownaKelowna SouthKelowna EastBenvoulinBelgoGlenmoreEllison
    August 13, 2018109511031107950107710121014
    August 10, 20181066107410799281050987988
    August 8, 20181035104310499031018959959
    August 7, 20181021102810358921005946947
    August 1, 2018943948955827928876874
    July 30, 2018912917925802895847844
    July 25, 2018839841853745821781779
    July 23, 2018813815826724796757757
    July 20, 2018783783794697767730729
    July 18, 2018758761773680746708705
    July 16, 2018729729742656714681677
    July 13, 2018688689702625674644642
    July 11, 2018661662674600646618615
    July 9, 2018643643657584629603600
    July 6, 2018614611626556598574569
    July 4, 2018587548600533572549544
    June 29, 2018549545563500535515508
    June 27, 2018533529548486520499491
    June 25, 2018520516536475507486479
    June 22, 2018490484503448476457449
    June 20, 2018467460478428452433425
    June 18, 2018438431450405422404398
    June 15, 2018406399419377391375370
    June 13, 2018396388408367381366360
    June 12, 2018392384404363377362355
    June 8, 2018375367387348362346341
    June 6, 2018358349370333345330324
    June 4, 2018346337358322334319313
    June 1, 2018328319339306317303298
    May 31, 2018321311331299309295290
    May 28, 2018305293314286293280275
    May 25, 2018277264285260265254247
    May 23, 2018254240260238241232225
    May 18, 2018213197215199199192185
    May 16, 2018195179196182180175169
    May 14, 2018173155172163155152147
    May 11, 2018143126142136127124121
    May 10, 2018138121135130121118114
    May 7, 2018121104117114104102100
    April 23, 201835253334242626
    April 4, 20188589455
    Data from Westbank, Kelowna South, Kelowna East, Belgo, Glenmore and Ellison comes from Growers Supply's weather network.

  • 2018 Degree Days - North
    Weather Station
    Location    		Winfield NorthWinfield SouthBella VistaVernon North & BX Salmon Arm
    August 13, 2018101299910871004863
    August 10, 20189879731067980840
    August 8, 20189589421031955814
    August 7, 20189459281016941803
    July 30, 2018845824903835712
    July 25, 2018775753830764650
    July 23, 2018751729805738627
    July 20, 2018725702776713602
    July 16, 2018671652721660556
    July 13, 2018635614680623524
    July 11, 2018609587651596501
    July 9, 2018593572633580483
    July 6, 2018563544601553458
    July 4, 2018538518574527435
    June 29, 2018505489542498409
    June 27, 2018490475528484398
    June 25, 2018477462515472387
    June 22, 2018448435485444358
    June 20, 2018427412463424338
    June 18, 2018397384433395327
    June 15, 2018354366399365320
    June 13, 2018358348388356311
    June 12, 2018354344384351308
    June 8, 2018341332371342294
    June 6, 2018324314352324279
    June 4, 2018311302339312274
    June 1, 2018295288321298261
    May 31, 2018288282313291255
    May 28, 2018271266294275241
    May 25, 2018245240264248216
    May 23, 2018220217225238196
    May 18, 2018180177194183153
    May 16, 2018161158172164134
    May 14, 2018140135149141116
    May 11, 201811310812111491
    May 10, 201810610211510986
    May 7, 20189289999476
    April 23, 20182117232016
    April 4, 201842431
    Data from Salmon Arm comes from Environment Canada.
    Data from Oyama, Winfield South, OK Landing & Bella Vista, and Vernon North & BX comes from Growers Supply's weather network.

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