Bee hours are an important metric for growers to track almond tree pollination to know when to take action to extend the bloom period, when to time bloom sprays, and to help troubleshoot years with poor fruit or nut set.

Find out how California's Central Valley bee hours are accumulating compared to last season and see your forecasted bee hours for the rest of the almond pollination season.

How to use Semios' California Bee Hours Dashboard

The dashboard below may take a couple of seconds to load.

Our dashboard references anonymous in-canopy Semios weather stations across the Central Valley and is updated every 12 hours.

  1. Use the green left and right arrows in the top left to scroll through North Valley (Colusa County), Mid Valley (Madera County), and South Valley (Kern County) bee activity.
  2. Use the green button in the top right to swap between the Cumulative Bee Hours Chart and the Daily Bee Activity Start & End Times Table.

❓ Wondering how you can use this data? Here are 3 ways to use bee hours to enhance your decision-making to help improve your yield and guide your bloom spray timing.


See your site-specific bee hours on Semios Live

Bee hours that are accumulated during the bloom overlap period should be used to assess pollination during bloom. It is best to use bloom progression as observed from the field, however for almond growers who do not have that information on hand, Semios provides predictions of bloom periods for Nonpareil and Monterey varieties on the Semios pollination dashboard.


Screenshot of the Semios Live platform's Pollination page, showing a bee hours: cumulative hours & period of activity graph


Understanding bee hours

Bee hours tell you the hours in which conditions are favorable for bees to fly.

A bee hour is defined as one hour where:

  • There is no rain
  • The temperature is warmer than 55° F, and
  • Wind speeds are less than 15 mph

More bee activity means more opportunities for pollination, making bee hours a valuable metric for getting a sense of how fruit or nut set, and ultimately yield, may compare between years.

almond tree pollination

Three ways to use bee hours

1. Adjusting the bloom period

In crops that require cross-pollination such as almonds, bee hours are only effective when bloom between different varieties overlap.

A shorter bloom overlap can mean a shorter period where bee hours can accumulate. In years where bee hours are high, this may not be an issue, but in years where bee hours are low, you may want to consider taking action to extend the bloom period. 

2. Plan your bloom-time sprays

Chemical applications should be avoided when bees are active in the orchard. Limiting spray applications to the late afternoon and evenings is recommended to target periods when bees are inactive. An extra level of assurance can be achieved by only spraying when bee hours are not expected to accumulate. 

💡 Semios customers can use their Pollination Dashboard to view their orchard’s forecasted bee active hours and plan sprays when bees aren’t present.

3. Troubleshooting poor fruit or nut set

After the bloom season, bee hours can help you troubleshoot what went right and wrong. If you had more bee hours this season but a poor fruit set compared to a previous year with fewer bee hours, there may be something else that may be going on in your orchard.


This article is for informational purposes only. Please consult your PCA or Crop Advisor for advice.  


Additional Resources

Honey Bee Best Management Practices


Related Posts

Protecting your Orchard During Bloom


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