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.

  • 2019 Degree Days - South
    Weather Station Location
    		Osoyoos Oliver SouthOliver CentralCawstonKeremeosPenticton AirportSummerland North
    September 12, 20191504145114761444145712941213
    September 10, 20191488143614621430144412801201
    September 5, 20191449139714231394140812441169
    August 28, 20191374132313501325134211751109
    August 26, 20191354130313301306132411551091
    August 23, 20191323127212991277129611261064
    August 21, 20191302125112791257127711061047
    August 19, 20191279122912561236125610851027
    August 16, 2019124311931221120212241050996
    August 14, 2019121911691197117912011027975
    August 12, 2019119311441172115511781003953
    August 8, 201911431093112211081132955909
    August 6, 201911071058108710741099920877
    August 2, 20191041994102310141042859820
    July 31, 201910109659919871013833794
    July 29, 2019981940965960986812774
    July 24, 2019914879900892915754721
    July 22, 2019890857878870894733703
    July 19, 2019857827848836859702678
    July 17, 2019834805827815836684661
    July 11, 2019754735750742764619597
    July 9, 2019731715731723743600579
    July 4, 2019675662679670690553537
    July 2, 2019652641657647666533520
    June 26, 2019596589604596614483476
    June 24, 2019580574589580598466463
    June 21, 2019551544561552570439441
    June 19, 2019539535550541558433435
    June 17, 2019518514529523539413415
    June 12, 2019450452466455466352362
    June 7, 2019406408423408415319327
    June 5, 2019398401417404408312317
    June 3, 2019375385396388390298300
    May 29, 2019316328337326332243246
    May 27, 2019295308315301309227228
    May 24, 2019273288296283289209211
    May 16, 2019217234242231236161160
    May 13, 2019200215224213217146145
    May 10, 2019172187195179182122131
    May 8, 2019156170178161163107106
    May 6, 20191391531611441459487
    May 3, 20191171311381231228078
    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.

  • 2019 Degree Days - Central
    Weather Station LocationWest KelownaKelowna SouthKelowna EastBenvoulinBelgoGlenmoreEllison
    September 12, 20191272130413201237124512211246
    September 10, 20191259129113081224123312091234
    September 5, 20191227125812761190120411791203
    August 28, 20191166119512131125114811201144
    August 26, 20191147117611951106113111021127
    August 23, 20191121114911681077110610771101
    August 21, 20191103113011501058109010591083
    August 19, 20191083111011301038107110401064
    August 16, 20191052107810981005104210101034
    August 14, 201910301056107798210229891013
    August 12, 20191008103310549591001967991
    August 8, 20199639881009912960924948
    August 6, 2019931955976879927891915
    August 2, 2019874897918820869835858
    July 31, 2019844867889797841808828
    July 29, 2019823845867779820788807
    July 24, 2019768789810732766738756
    July 22, 2019747767789715744719736
    July 19, 2019N/A741762691719696709
    July 17, 2019703722745674700678690
    July 11, 2019633652675607633610620
    July 9, 2019612630654587612590599
    July 4, 2019569584610546568548554
    July 2, 2019550563590529549531536
    June 26, 2019504517541487504486489
    June 24, 2019489503526473490472474
    June 21, 2019465476502449464448448
    June 19, 2019459471497444461443444
    June 17, 2019435448474426439423423
    June 12, 2019374386412375377363365
    June 7, 2019340352376342344329328
    June 5, 2019328339364334334318318
    June 3, 2019310323345319318302302
    May 27, 2019232242263253238230229
    May 24, 2019216227246238224214214
    May 16, 2019168175191190175170169
    May 13, 2019152160176178160157156
    May 10, 2019134130144149128140126
    May 8, 2019108113128134114115114
    May 6, 201996101113121101102102
    May 3, 2019848799107889089

  • 2019 Degree Days - North
    Weather Station
    Location    		Winfield NorthWinfield SouthBella VistaVernon North & BX Salmon Arm
    September 12, 201912061163125412011084
    September 10, 201911951152124311901073
    September 5, 201911651258121511631045
    August 28, 20191106119511591110990
    August 26, 20191089105011431094973
    August 23, 20191064114911191071949
    August 21, 20191046113011021056933
    August 19, 2019102799110841038915
    August 16, 2019997107810551011886
    August 14, 20199779421036992867
    August 12, 20199559211015972846
    August 8, 2019912879973932805
    August 6, 2019880955942901775
    August 2, 2019826793893850726
    July 31, 2019799867863821701
    July 29, 2019778845840800683
    July 24, 2019728697785748639
    July 22, 2019708767765728618
    July 19, 2019684655741703595
    July 17, 2019667722724686579
    July 11, 2019600652656626523
    July 9, 2019580557633605504
    July 4, 2019536515588559462
    July 2, 2019520499572544446
    June 26, 2019474456521500405
    June 24, 2019461445506484391
    June 21, 2019435421481462375
    June 19, 2019431418474456370
    June 17, 2019411448450435350
    June 12, 2019351337385375296
    June 7, 2019315304345340265
    June 5, 2019404294331328257
    June 3, 2019290280312311241
    May 29, 2019236224253252192
    May 27, 2019216242234231176
    May 24, 2019201191214211158
    May 16, 2019154149161163119
    May 13, 2019140135143147105
    May 10, 201912011412513092
    May 8, 201995919810366
    May 6, 20198479859056
    May 3, 20197369727846
    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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