How to Control Your Greenhouse Temperature In Summer

greenhouse temperature in summer

Controlling Greenhouse Temperature in Summer

We are well into summer and the hot weather has definitely made its presence known. This poses a few challenges for gardeners especially when growing in a greenhouse.

Growing in a greenhouse allows you to control the environment and create the perfect conditions necessary for the plants you are growing such as warmth-loving crops like tomatoes and cucumbers. The optimum temperature for growing tomatoes in a greenhouse is during the day between 65-85°F. Getting these conditions wrong however can ruin your crop and all you hard effort.

What is the ideal temperature for a greenhouse?

The ideal temperature inside a greenhouse is about 80-85°C, so it’s very important to keep the internal temperature steady.

During summer, temperatures can fall between 13-32°C (55-90°F). In light of this we suggest that you use a number of different cooling methods to keep an optimal greenhouse temperature on hotter days including ventilation, shading and cooling fans. It’s vital that you get the right amount of airflow to your plants to ensure they continue to grow healthy.

In this guide we will offer some important considerations to ensure that you can effectively control your greenhouse temperature in these hotter months to prevent any disappointment with your crops.

Ventilating Your Greenhouse

An effective way to combat summer heat is to give plants a reliable flow of air from ventilation – whether this is roof vents, side vents or opening the greenhouse door for parts of the day to cool down your prized and overheated plants.

Our Greenhouse Autovent automatically opens and closes with temperature changes helping you maintain an event temperature in your greenhouse. It is also adjustable so that you can open it at specific temperatures.

Greenhouse Ventilation

Humidity in Your Greenhouse

Damage can occur to some plants if temperatures creep above 27°C (81°F). Control humidity and create the optimum growing environment with a Humidifier. Our Humidifier is highly adjustable and can be filled manually or constantly. A Humidifier will control and increase the moisture level ensuring clean air is circulated in your greenhouse.

It is also important to have a greenhouse temperature sensor such as a Thermometer & Hygrometer to display, monitor and record minimum and maximum temperature and humidity levels of your greenhouse. This will help to understand what actions you should take to provide plants with the best conditions.

On hotter days, ensure you open all doors and vents earlier in the day and during warmer evenings.

Controlling Temperatures in Your Greenhouse

Shading Your Greenhouse

Another top method of mitigating heat in your greenhouse is to use shading. We suggest you use this cautiously as plants will need sufficient levels of light to grow healthy.

Our Shading Paint is applied onto the outside of your greenhouse glass surface with a brush or sprayer to prevent your greenhouse from over-heating. It wipes off easily with a duster and helps to protect from scorching too.

Shading Paint is a fast and cheap way of filtering out some of the unwanted strength of the sun’s rays. You can add more layers as you move through the summer and then simply wash off as the weather begins to cool.

Greenhouse Shading Paint


Alternatively, use an easy to use Mesh Greenhouse Shading to prevent overheating and scorching with minimal time and effort. It's very lightweight and versatile and can be easily cut to size and clip into place. A brilliant quick fix on a hot day!

greenhouse shading

Greenhouse Circulation & Ventilation Fans

Our electric greenhouse fans improve ventilation and air circulation in your greenhouse. By installing them, you can maintain the temperature of your greenhouse without spending a fortune on energy bills. In the warmer summer months you can rely upon our greenhouse ventilation fans to keep the air cool and circulating effectively.

Air movement is vital in order to keep your plants healthy, as removing stagnant air reduces the risk of diseases such as mildew, weak plant stems and damping-off, and once air is flowing these fans can ensure that the climate is consistently level.

greenhouse fans

Watering Your Greenhouse

Raise the humidity inside your greenhouse by watering the surfaces to promote evaporation and thus moisture in the air which helps your plants keep cool to persevere the heat. Moisture and humidity in the air will also help deter pests as they love to be in dry conditions.

You can dampen down by simply using a watering can, we recommend in the mornings and evenings. Consider automate your watering with a Greenhouse Irrigation Kit which has drippers and misters. Simply click this on to a mains tap, run the pipe between your pots, borders or grow bags and put the drippers and misters in place.

Watering Cans

You can also attach an electric timer to your Greenhouse Irrigation Kit which links to your tap which helps automate your watering – especially useful when you are on holiday!

greenhouse irrigation kit

Hopefully you’re now feeling more confident on how to keep your greenhouse cool this summer if it’s something you haven’t looked into much before. And don’t forget that Greenhouse Sensation has all of the greenhouse supplies that you’re likely to need as well, with speedy delivery times to get you started as soon as possible.