Fire Danger Index (FDI)
NWUFPA Info Book Article 4, MFPA Business Plan Section 7.5 & NWUFPA/PFPA Rules
What is the Fire Danger Index?
The Fire Danger Index (FDI) is a numerical rating from 0 to 100 that indicates the level of fire danger on any given day. It is calculated from weather data including temperature, humidity, wind speed, and rainfall history. The FDI is the primary tool used by FPAs and fire services to determine whether burning activities are safe and to set the level of fire readiness required.
The FDI is colour-coded into five alert stages. Each stage provides guidance on fire behaviour, expected flame lengths, and the appropriate response.
FDI Alert Stages
| Alert Stage | FDI Range | Fire Behaviour | Flame Length | Fire Control Guide |
|---|---|---|---|---|
| BLUE | 0 – 20 | SAFE | 0 – 1m | Low fire hazard. Contact FPA for information. Controlled burning can be carried out. |
| GREEN | 21 – 45 | MODERATE | 1 – 1.2m | Controlled burning can be done. Take care on exposed dry slopes. Watch for wind changes. |
| YELLOW | 46 – 60 | DANGEROUS | 1.2 – 1.8m | Controlled burning is NOT recommended. Aircraft should be called early if a fire occurs. |
| ORANGE | 61 – 75 | VERY DANGEROUS | 1.8 – 2.4m | NO controlled burning of any nature. Watch for smoke. Maximum force must be deployed if a fire occurs. |
| RED | 76 – 100 | EXTREMELY DANGEROUS | 2.4m+ | All personnel on full stand-by. Every measure must be taken to bring any fire under control. All aircraft called without delay. |
Activity Restrictions at FDI Above 55 (NWUFPA/PFPA Guideline)
Per PFPA Rules (applied as the NWUFPA provincial reference), when the Fire Danger Index exceeds 55, the following activities are strictly prohibited regardless of whether a permit has been issued. The MFPA Business Plan does not specify its own FDI cutoff number; these NWUFPA/PFPA thresholds are applied as the supplementary guideline for the area.
| Activity | Status at FDI > 55 |
|---|---|
| Slash burning | Not Allowed |
| Fire breaks (by burning) | Not Allowed |
| Crop residue burning | Not Allowed |
| Open fires | Not Allowed |
| Charcoal kilns | Must Be Sealed |
Understanding Each Stage
BLUE (0–20) — Safe
Conditions are safe for burning activities. Fires will be low intensity and easy to control. This is the ideal time for controlled burns, firebreak preparation, and other planned fire activities. Always obtain the required permits even during safe conditions.
GREEN (21–45) — Moderate
Controlled burning can still be done, but with increased caution. Fires may become more intense on exposed, dry slopes. Watch for sudden wind changes that could cause a fire to escape. Adequate resources and personnel must be on standby.
YELLOW (46–60) — Dangerous
Controlled burning is no longer recommended. Fires will be difficult to control and can spread rapidly. If a wildfire occurs, aircraft and additional resources should be called early. All landowners should be on heightened alert.
ORANGE (61–75) — Very Dangerous
Absolutely no controlled burning of any nature. Fires will be intense and very difficult to control. Watch for smoke from any direction. If a fire starts, maximum force must be deployed immediately. All available resources should be on standby.
RED (76–100) — Extremely Dangerous
The most severe fire danger conditions. All firefighting personnel must be on full stand-by. Any fire that starts will be extremely intense, fast-moving, and potentially unstoppable without massive resources. Every possible measure must be taken to bring fires under control immediately. All available aircraft must be called without delay. Residents should be prepared to evacuate if necessary.