Planning for adverse weather and incorporating that into the project schedule is an essential practice for successful projects. This recommended practice (RP) for adverse weather planning is intended to provide a guideline, not to establish a standard. It provides planning guidelines developed primarily for engineering and capital construction projects but can be adapted to any type of project or program where weather can influence its outcome.

This RP is intended to:
- Identify methodologies for adverse weather planning.
- Provide sources for historical data and provide recommendations for their use.
- Explain and critique weather planning methods.
- Recommend approaches for managing actual weather documentation compared to what was planned.

Positive and negative aspects for each weather planning method should be considered in the context of specific projects elements, including contractual requirements. This RP does not address legal ramifications or forensic schedule delay analysis considerations that may need to be addressed when adverse weather delay is in contention.

This RP serves to provide guidance in the absence of contractual requirements as well as potential guidance in writing specifications for adverse weather planning. If adverse weather planning is addressed in the contract, planning and modeling should be in compliance.