Update on Degree Days and precipitation to end of August

2021 Degree Day Accumulations

Degree day accumulations up to this point are keeping pace with years such as 2006, 2010, 2013, and 2018. Please note that degree days may not directly correspond with a change in harvest dates but the extra heat this year certainly could advance maturity. Continue to monitor blocks earlier than usual to catch any signs of advanced maturity to be off to a good start.

Figure 1: Heating degree day accumulations for plant (above 5°C) and insect (above 10°C) development from March 1st to August 31st for the past 17 seasons. Provided by Jeff Franklin (AAFC).

• Approximately 6% more plant development heat units compared to the 5-year average, and 6% more compared to the 10-year average.
• Approximately 4% more plant development heat units compared to 2020, and 12% more compared with 2019.
• Approximately 7% more insect development heat units compared to the 5-year average, and 6% more compared to the 10-year average.

How about a breakdown of temperature by month? According to the Kentville weather station, June was noticeably warmer than average while July and August were close to the 10-year mean temperature (Table 1). Overall, the temperature this summer has been above-average contributing to the lead in degree days shown above.

Table 1: Monthly temperature averages in 2021 compared with the 10-year average. Provided by Jeff Franklin (AAFC) using the Kentville weather station data.

Seasonal Precipitation

Overall, this summer in Kentville there has been above-average precipitation even though there was an early deficit in June (Table 2). The excess in July was largely due to 50 mm of precipitation received in a localized thunderstorm that didn't affect the whole Valley. For regional differences in precipitation, refer to the records in the NSFGA network of weather stations.

Table 2: Monthly precipitation totals in 2021 compared with the 10-year average. Provided by Jeff Franklin (AAFC) using the Kentville weather station data.

It looks like September could be off to an early wet start with tomorrow's forecast for 50 mm of rain from the remnants of hurricane Ida. 

The overall above-average temperature and precipitation this season has made for some fairly good growing conditions.