Best Smoke Days: Methodology

How the 0-100 smoke score is calculated. Four weather signals, cooker-specific wind sensitivity, why humidity is not scored, and full transparency on the data sources.

Data sources

Forecasts are pulled from Open-Meteo as the primary source, with the US National Weather Service as failover. The worker tries Open-Meteo first; if Open-Meteo returns 5xx, times out, or sends malformed JSON, the request fails over to NWS within the same fetch cycle. Successful Open-Meteo responses are cached in Cloudflare KV with a 24-hour freshness window and a maximum 30-hour retention window, so a brief upstream outage doesn't blank the forecast.

Both sources provide regional forecasts. They don't see your yard's trees, structures, or elevation. Step outside before lighting the fire: the score is a planning signal, not a ground truth.

Location and the national comparison

The meat smoking calculator's weather panel starts without a score. A US ZIP you choose takes priority over a saved explicit choice, then an approximate location from Cloudflare. Automatic selection requires US country metadata and a ZIP verified against our location lookup. Postal metadata can be missing or inaccurate; use Change location to correct it. We never infer a ZIP from a state, request browser location permission automatically, or put IP addresses or precise coordinates in these responses.

Without a valid US ZIP, “Top smoke conditions across our US locations” compares 50 geographically distributed metro ZIPs in the continental United States. Coverage includes the Northeast, Southeast, Midwest, Mountain West and Pacific Coast. It excludes Alaska, Hawaii, territories and most rural ZIPs; it is not a search of every US ZIP. The internal dataset supports forecasting only and does not create city landing pages.

Each comparison uses brisket packer, a pellet smoker and a 225°F scoring assumption. We select the forecast matching today's calendar date in each location's own timezone and show that date. Tied scores sort alphabetically by the stable location identifier. The highest two distinct available locations are shown; one or none may be available. A different cooking date selected in the local tool is identified explicitly.

A scheduled job reads and scores forecasts once for the comparison, with at most 50 upstream requests per run, including provider retries. Visitors request a compact cached ranking, not dozens of forecasts. The job runs at 04:00 and 05:00 UTC to cover Eastern midnight through daylight saving changes. Forecast fetch times remain unchanged when a cache is reused or the ranking is rewritten. Data older than 24 hours is labeled stale; data older than 30 hours is excluded. A valid local ZIP whose forecast fails stays a local error with retry and change controls.

Missing temperature, humidity, wind or precipitation probability is not treated as a calm, dry forecast. Incomplete records are omitted. NWS hourly forecasts do not supply rain accumulation or usually gust speed; their score uses rain probability without an accumulation adjustment and a sustained-wind gust estimate. Its current-day summary covers the hours still available from that provider. Source differences and yard-scale conditions can change the ranking.

Location responses use private, no-store caching. Explicit ZIP forecasts may be cached for five minutes and national rankings for one minute. These network caches do not change the displayed source-fetch time or extend the 30-hour source expiry.

The four scoring signals

  1. Precipitation (up to 50 points). Probability times accumulation. 90% rain + 0.5″ accumulation costs the full 50 points so the day lands in the red band on its own.
  2. Wind and gusts (scaled by cooker sensitivity). Effective gust = reported gust if present, otherwise sustained wind × 1.4 (CONUS inland gust factor). Penalty grows linearly from 10 mph and caps at 35 mph. Past 25 mph, an offset, pellet grill or kettle also loses 2 points per mph before the coefficient, because strong gusts make an exposed fire hard to hold steady. Coefficient: offset 1.5×, pellet 1.0×, kettle 1.2×, kamado 0.5×, electric 0.1×.
  3. Cold (up to 20 points). Penalty starts when the coldest hour of the cook is below 40 °F and reaches full at 10 °F. Catches the cooks where startup is hard and fuel rate explodes.
  4. Heat (up to 25 points). Penalty starts when the hottest hour of the cook is above 85 °F and reaches full above 110 °F (the danger-zone end of the operating range).

Your cut sets the hours that count

Weather matters only while the fire is going. The score assumes the meat comes off the smoker by 6 PM, after a typical cook for that cut, with an hour before it to light the fire, and reads rain, wind, cold, and heat over those hours alone. A packer brisket is on through the overnight low; chicken thighs see only the late afternoon. So a cold, wet morning that clears by noon is a poor brisket day and a fine chicken day.

Cook times are the typical-size planning numbers from our calculators (a 12 lb packer at 1.25 hours per pound, an 8 lb pork butt at 1.5). Each day card names the hours it scored. When the hourly forecast does not cover all of them (a forecast with gaps, today once the provider has dropped the hours already past, or the spring-forward night for an overnight brisket), that day is scored on its whole forecast instead, and its card names no hours. The high, low, and gust printed on each card are always for the whole day.

Once today's fire-up hour for your cut has passed in your local time, today's card says it is too late to start, and the best day is picked from the days you can still cook. Today's score stays on its card, because the weather is still worth knowing.

Why humidity is not scored

Humid air does lengthen the stall: it keeps the meat surface wet and evaporating (Greg Blonder: "the stall is rapid in dry environments, prolonged in humid"; AmazingRibs notes a water pan raises humidity and slows the cook). But outdoor weather moves it only a little. The cook-time model behind our brisket and pork shoulder calculators puts the difference between a cold, dry day and a muggy one at roughly 15 to 40 minutes of stall, depending on the cut and its size. The cooker matters about as much, and wrapping at the stall saves about four hours on a whole brisket.

An earlier version of this score charged up to 20 points for stall risk. That number was set mostly by the cooker type rather than the weather, so it flagged nearly every day as high stall risk on a pellet, kettle, kamado, or electric smoker and never helped pick a day. We removed it. Plan the stall with the calculators instead: they can use your local forecast.

The four bands

Each day lists its reasons, biggest cost first. Any rain, wind, cold or heat penalty over 2.5 points is named. The unnamed ones cost 10 points at most between them, so "Conditions look good" appears only on a day scoring 90 or more.

Confidence labels

Each day in the 7-day window carries a horizon label that reflects how far ahead the forecast looks, not measured statistical confidence: high for the next 24-48 hours, medium for days 3-4, low for days 5-7. These labels are planning guidance, not calibrated probabilities or evidence of measured accuracy.

The scoring model is only as good as the cooks it's checked against. If you log pit and meat temperatures on your smokes, you can contribute a real cook to the calibration set - real stall data is what tightens these predictions.

Have a question this page doesn't answer? See the FAQ or affiliate disclosures.

Methodology FAQ

Where does the weather data come from?

Pitmaster Tools uses the Open-Meteo API as the primary forecast source. If Open-Meteo is unavailable or returns malformed data, the worker fails over to the US National Weather Service (api.weather.gov). Both sources provide regional forecasts: they don't see your specific yard's microclimate. The day's confidence label drops from high to medium to low as the forecast horizon grows.

How is the 0-100 score calculated?

We start at 100 and subtract penalties for four weather signals, read over the hours your cut is on the smoker: precipitation (probability × accumulation, up to 50 points), wind / gusts (scaled by cooker sensitivity, up to 30 points after the coefficient, and more past 25 mph on an offset, pellet grill or kettle), cold (coldest hour below 40 °F, up to 20 points), and heat (hottest hour above 85 °F, up to 25 points). Humidity is not scored, for the reason given below. The remaining score lands in one of four bands: red (under 50), yellow (50-69), green (70-84), or ideal (85+).

What is wet-bulb temperature and why does it matter?

Wet-bulb temperature is the lowest temperature evaporation can cool a wet surface down to. It's a function of air temperature and humidity. For a low-and-slow cook, the meat's surface evaporates moisture and is cooled by it: this is the source of the stall plateau around 150-165 °F. Higher wet-bulb inside the cooker means a longer stall, but outdoor weather moves it only a little: by the cook-time model behind our calculators, a muggy day lengthens the stall by well under an hour compared with a cold, dry one. Wrapping at the stall saves about four hours on a whole brisket. That is why the score does not penalize humidity.

Why does cooker type affect the score?

Different cookers respond differently to weather. An offset stick burner's fire is exposed to wind and shifts pit temperature with every gust: we apply a 1.5× wind sensitivity coefficient. An electric smoker doesn't notice wind at all (0.1×). A kamado is well insulated with a small intake, so wind barely moves it (0.5×). Cooker type also changes how humid the pit runs, which the cook-time calculators account for; it does not make one day better than another, so the score leaves it out.

Is the score the same for every cut?

No. The cut sets the hours that count: the score reads the weather from when the fire is lit until the meat comes off at 6 PM, so a packer brisket, lit around 2 AM, carries the overnight low and morning rain that 3 PM chicken thighs never see. Humidity is still not scored: it lengthens the stall on long cuts by well under an hour even on a muggy day, too little to change which day is best.

How accurate is the forecast?

We pull from regional forecast sources, but every forecast carries uncertainty that grows with the horizon. The day index gets a confidence label: high for the next 24-48 hours, dropping to medium and then low further out. Treat the day-5 through day-7 end of the window as a planning signal, not a commitment. Also: the regional forecast doesn't model your yard's trees, structures, or elevation. Step outside before lighting the fire.