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PMS 437

Fuel Moisture Sampling

  1. Online Fuel Moisture Sampling History
  2. Fuel Moisture Sampling Procedures

Online Fuel Moisture Sampling History

Fuel moisture sampling can provide useful insight to current conditions if it is done consistently throughout each fire season. Results from sampling efforts around the United States are stored in the National Fuel Moisture Database. Results for sampling history of both live and dead fuels are available for locations around the United States.

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Fuel Moisture Sampling Procedures

General Guidelines

  • Record site name, date, time, observer name, observed weather, general site description.
  • DO NOT collect samples if water drops or dew are present on samples.
  • Keep samples in a cool and dry location.
  • Seal containers with tape that will not leave residue.

Live Fuel Samples

  • Only collect foliage or needles and very small twigs remove flowers, seeds, nuts, or berries.
  • Pack containers loosely to avoid spillage but ensure container is full.
  • Include stems of herbaceous plants.
  • Replace lid on container immediately after collecting sample.

Dead Fuel Samples

  • Samples should not be attached to live trees or shrubs.
  • Avoid decayed samples that crumble or splinter when rubbed.
  • Collect samples from several different plants.
  • Ensure container is full or about 20 grams.
  • Do not collect buried samples.
  • Pick samples of different size within the time lag class.
  • Recently fallen material should be avoided.
  • Remove all lichen, moss, and very loose bark from sample.

Duff and Soil Samples

  • Remove all soil and live tree or plant roots from sample.
  • Avoid any soil particles in duff samples and vice versa.

Litter Samples

  • Collect only uncompacted dry litter from both sunny and shady areas.

Handling and Measuring Samples

  • Preheat drying oven between 60°C (140°F) – 100°C (212°F). Be sure to note temp used.
  • Place sample cans with closed lids on scale and record wet weights.
  • Remove lid just prior to placing in oven. If material is lost, re-weigh sample
  • Dry sample for 24 hours (very wet samples 48 hours).
  • Replace Lids immediately after sample is removed from oven and weigh
  • Calculate fuel moisture using worksheet provided here:
Fuel moisture sampling and estimation. This table provides means for tracking sample weights and calculating gravimetric fuel moisture.

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NEW! S-490, Advanced Fire Behavior Calculations (Blended) Available Now

Date:  March 17, 2026
Questions? 
Please contact: Fire Behavior Subcommittee

NWCG is pleased to announce that the new S-490, Advanced Fire Behavior Calculations (Blended), 2026 course is now available.

This training includes performance-based activities that allow students to apply the knowledge and concepts required for the Fire Behavior Analyst (FBAN), Long Term Fire Analyst (LTAN), and Prescribed Fire Burn Boss Type 1 (RXB1) positions. It supports individuals working towards these incident qualifications.

This blended course begins with a self-paced online training (OLT) in the Wildland Fire Learning Portal (WFLP), followed by an in-person instructor-led training (ILT).

References:

S-490, Advanced Fire Calculations (Blended)

NWCG Fire Behavior Analyst (FBAN) Position Page

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Date:  March 13, 2026
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The NWCG Leadership Committee is proud to announce the recipients of the 2024 Paul Gleason "Lead By Example" awards. Award categories include Initiative and Innovation, Mentoring and Teamwork, Motivation and Vision, as well as a Lifetime Achievement Award.

Congratulations to the awardees:

  • Justin Baxter, National Unmanned Aerial System (UAS) Operations Specialist, with the U.S. Forest Service — Initiative and Innovation
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References:

Paul Gleason Lead By Example Award

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Leadership Committee

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Date:  March 6, 2026
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NWCG is pleased to announce the new S-231, Engine Boss (Single Resource) course is now available on the Wildland Fire Learning Portal (WFLP). Developed through the Incident Performance and Training Modernization (IPTM) effort, this training supports individuals working towards Engine Boss, Single Resource (ENGB) incident qualifications. 

This is a performance-based instructor-led training (ILT) that focuses on the application of ENGB responsibilities during wildland fire operations, emphasizing readiness, information gathering, risk management, engine tactics, and Wildland Urban Interface (WUI) operations. Trainees apply these skills through scenario-based group work and an optional field day that reinforces hands-on engine operation tasks. 

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NWCG Engine Boss, Single Resource (ENGB) Position Page

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Date:  March 6, 2026
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NWCG is proud to celebrate 50 years of service to the wildland fire community. Beginning in 1976 with an interagency agreement between the Department of Interior and Department of Agriculture, NWCG has grown to include additional member agencies and is recognized as the standard-setting leader in wildland fire operations.

To honor where we’ve been and highlight where we are going, the NWCG team has created a video showcasing our history and accomplishments. The video is now available on the NWCG website.

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NWCG 50 Year Anniversary Video