Temperature and humidity inside the hive tell you about the colony's state without opening it. Read correctly, they save time.

Temperature

The brood nest is held at about thirty-five degrees. The bees maintain this closely; deviation disrupts brood development.

A sensor placed in the brood area shows whether that temperature is being held.

• Steady high reading: There is brood and the colony is sound
• Falling and fluctuating: Brood has ended or the colony has weakened
• Gradual decline in winter: Brood rearing has stopped

Its most valuable use

The most concrete benefit of a temperature sensor is detecting the start of the broodless period.

That period is the most favourable window for contact treatments such as oxalic acid, because all the mites are on the bees.

Measuring rather than guessing that window directly improves the effectiveness of the treatment. With climate shifting, fixed dates are becoming steadily less reliable.

Humidity

In winter moisture kills more than cold. A colony withstands cold; it does not withstand continuous dripping condensation.

A humidity sensor gives early warning of inadequate ventilation and a leaking roof.

In summer high humidity slows the ripening of honey.

Placement

• The temperature sensor goes in or just above the brood area
• Away from direct sun and draughts
• Cable and housing must not obstruct the bees
• It will be coated in propolis; regular cleaning is needed

Limits

A sensor tells you that something has changed, not why.

A temperature drop may mean brood has ended, the queen is lost, or disease. Finding the cause still means opening the hive.

How many

Not every hive needs one. A few representative colonies are usually enough; colonies in the same apiary experience similar conditions.

Data

Data that is not interpreted is useless. Accumulating graphs is not making decisions; what each measurement will trigger should be decided in advance.