Basic Information

The weather is an important external factor in tree house construction. It is important to observe the weather in order to take precautions early enough in critical situations. The process of leaving a tree house quickly in a crisis situation must be practised beforehand.

The most important weather influences are:

  • Wind
  • Rainy and wet conditions
  • Temperature
  • Thunderstorms
  • Snow
  • Time of day/sunlight

Further Information

Weather Services

During construction as well as during operation it is important to routinely observe the weather and to adapt activities to the weather. Forecasts from helpful country-specific weather services can be found here:

Depending on the upcoming weather, appropriate measures need to be taken in congruence with the following weather levels.

Weather Security Levels
Security Level 5 (very great danger)

Measured Values

Wind peaks in the low and middle altitudes: >140 km / h

Wind peaks in the higher altitudes (>1800 m.a.s.l.): >200 km / h


  • Falling trees - whole groups of trees or parts of woods and pylons
  • Severe damage to buildings
  • disruption or standstill of road, rail, water and air traffic
  • Tipping over of larger (unoccupied) vehicles
  • Overturning of firmly anchored large-scale objects such as tents and scaffolding as well as mobile objects such as garden furniture etc.
  • Large waves washing over the banks of lakes
  • Long-lasting, large-scale power and telephone service outages
Security Level 4 (great danger)

Measured Values

Wind peaks in the low and middle altitudes (incl. foehn): 110-140 km / h

Wind peaks in the higher altitudes (>1800 m.a.s.l.): 160-200 km / h


  • Some trees falling
  • Damage to some buildings and roofs
  • Obstruction or restriction of road, rail, water and air traffic
  • Drifting of firmly anchored large-scale objects such as tents and scaffolding as well as mobile objects such as garden furniture
  • Power supply and/or telephone connection outages
Security Level 3 (considerable danger)

Measured Values

Wind peaks in the low and middle altitudes (incl. foehn): 90-110 km / h

Wind peaks in the higher altitudes (>1800 m.a.s.l.): 130-160 km / h


  • Branches breaking, toppling over of some trees
  • Damage to some roofs
  • Toppling over of lightly anchored, large objects such as tents and scaffolding
  • Impairment of road, rail, water and air traffic
  • Possible adjustment of the operation of ski lifts and cable cars
Security Level 2 (moderate danger)

Measured Values

Stormy wind in the low and middle altitudes (incl. foehn): 70-90 km / h


  • Ground level turbulence hinders small aircraft
  • Increased waves on lakes (whitecaps)
  • Overturning of objects that are not or are insufficiently secured
  • Smaller branches breaking
Security Level 1 (little or no danger)

Measured Values

The weather development remains within the normal range for the season. Even if there is no danger notice, dangerous weather situations can still occur locally.



Bevahiour in Dangerous Weather Conditions
  • Starting with security level 2 and further, it is necessary to check the trees in the immediate vicinity for dead branches in advance and to remove them wherever possible, or to rope off necessary areas.
  • From security level 3 upwards, alternatives should be examined (e.g. emergency accommodation)
  • For the event of a severe storm, we recommend agreeing on and practicing a scenario in advance in order to be able to manage the crisis efficiently. Evacuation procedures and responsibilities must be clear. The scenario must also be feasible in the event of a crisis.
Advice for Various Weather Conditions
Temperature & Snow

An often-underestimated danger is heat - this coincides with water consumption. When building at lofty heights it can be quickly forgotten. In hot weather, work performance drops rapidly and the risk of accidents increases. In the forest the sunlight is less than in the open field - nevertheless, sun protection (proper clothing, sunscreen) is very important, as in all outdoor activities.

During longer periods of high temperatures and drought the forest dries out and the risk of forest fire increases significantly. If the risk of forest fire is heightened, contact with the local authorities is necessary in advance to discuss possible measures such as a fire ban.

If you plan to leave your tree house standing during the winter, please note that snowfall can lead to heavy snow loads. This can quickly amount to several hundred kilos per m2. Frost damage can also occur to the material used in winter.

Rainy & Wet Conditions

There is no bad weather - only bad clothing. A maxim for all those who have been outside in the pouring rain for days. In fact, good clothing protects against moisture (which quickly leads to cold) for a relatively long time. Waterproof clothing, which protects reliably against moisture even during long periods of rain, is therefore also part of personal protective equipment.

The building material remains wet, however, and therefore it also becomes slippery and can be dangerous. 


The most dangerous weather situations are thunderstorms. Gusty winds with up to storm force (<75km/h) combined with torrential rain or hail combined with lightning and thunder can destroy a whole camp within a very short time. Therefore it is very important to prepare for these events preventively:

  • During thunderstorms, trees can easily fall over. Especially in a tree house the structural engineering of a tree changes - because it can no longer swing freely in the wind. In this situation, trees can bend or large branches in the treetops can break off!  Pioneer-technically constructed buildings are generally not suitable as emergency accommodation!
  • Heavy rainfall can easily cause flooding or flash floods, so always build your buildings at a certain distance from the water. Large masses of water can also undermine trees or soften the soil so that the stability of the ground is no longer guaranteed.
  • Plan your buildings in such a way that even a short-term evacuation is possible. For larger tree houses, for example, this means several access points.
  • In the event of a storm, the forest must be left early - attention in open fields is the danger of lightning. Therefore, check early on which location is suitable as emergency accommodation in the event of a storm.
  • Inform all participants in advance about how to behave in case of a storm. Define the individual roles in advance (Who takes the participants to the emergency shelter? Who checks that everyone is safe?)
  • Be careful with wire ropes, masts, single trees or water. These are natural lightning conductors. This is where the greatest risk of being struck by lightning exists.
  • 30-30 rule: If the distance between lightning and thunder is less than 30 seconds, you are in the danger zone. Only 30 minutes after the last lightning or thunder should you leave your protective position.
Time of day & sunlight

Building is an activity for the day - lack of light and fatigue increases the risk of accidents. We therefore only build in daylight. When planning your activities, it is important that you know how long you will have light available to work:

Day/Month Sunrise Sunset
1. January 08:10 16:50
1. February 08:00 17:30
1. March 07:10 18:15
1. April* 07:10 20:00
1. May* 06:15 20:40
1. June* 05:35 21:20
1. July* 05:35 21:30
1. August* 06:05 21:05
1. September* 06:45 20:10
1. October 07:30 19:10
1. November 07:15 17:15
1. December 07:55 16:40

*These values refer to Central European Summer Time (CEST) Twilight begins on average about 30 minutes before sunset and continues until 30 minutes after sunset.


CVJM-Akademie gGmbH
Institut für Erlebnispädagogik
Im Dru­sel­tal 8
34131 Kassel

Tele­fon: + 49 (0) 561 30 87–506
Fax: +49 (0) 561 30 87–501

Funded by Erasmus+ "Youth in Action"

The website and the content was developed in the project "Treehouse Camps - a Method to Strengthen Key Competences and Integration in Youth Work".

Project duration: September 2018 - August 2021