Temperature & Humidity Control are especially closely tied, directly affecting each other. So it’s virtually impossible to discuss temperature control without taking humidity into consideration.

Cannabis Temperature Control

Like all plants, cannabis likes comfortable temperatures. For most grows, the ideal temperature range is between 65-80°F (18-26°C). Keeping temperatures within this range helps maximize plant growth and development and contributes to large and healthy buds.

Temperature control is one of the most basic aspects of controlled environment cultivation. It also affects and is affected by other parameters, such as lighting and humidity. Which is why temperature control is at the center of most grow room climate control systems.

Ideal Humidity Range for Cannabis

Cannabis has an ideal humidity range, just as it has an optimal temperature range. Most cannabis growers prefer a range of 40-70% relative humidity, depending on the growth stage.

In terms of VPD (vapor pressure deficit), the ideal range is 0.8-1.1 kPa during the growth stage, and 1.0-1.5 kPa during flowering stages.

Preventing Molds and Mildews

While the ideal humidity range has a huge impact on development, it’s not the only reason to control humidity. Perhaps the biggest issue with humidity is mold. The most common of which being bud rot (also known as gray mold or botrytis) and powdery mildew.