Why We Built This

We're Edge Right, a landscape supply company. Our business — and the businesses of the landscapers, designers, and Edge Right PRO members we serve — lives and dies by the weather. When it's gorgeous outside, phones ring off the hook. When it rains for a week straight, sales go quiet. We've always felt that connection in our gut, but we wanted to prove it with data.

The SunWard Index started as an internal experiment: can we put a number on how willing people are to step outside and think about their landscape? Turns out we could — and the correlation between high-index days and order volume was exactly what we suspected. Good weather brings good days. Bad weather explains the slow ones.

Now we use it to plan ahead. When the SunWard Index forecasts a string of beautiful days, we staff up and stock the yard. When a cold front is coming, we know not to panic when things slow down — it's the weather, not the business. We built this tool for ourselves, but we think anyone in the outdoor industry will find it just as useful.

What Is the SunWard Index?

The SunWard Index is a 0–100 score that measures how willing people are to get outside based on weather conditions. It scores ~1,700 ASOS/AWOS stations across the continental United States using a weighted formula that considers temperature comfort, sunshine, precipitation, humidity, wind, visibility, and UV index. Think of it as a pulse on the country's willingness to get outdoors and think about their landscape.

How It Works

Each station-day is scored using a combination of absolute comfort (is 75°F and sunny?) and location-relative acclimation (how does today compare to what's normal here?).

The acclimation component is asymmetric by design — warmth tolerance is relative (85°F feels fine in Florida but hot in Maine), while cold intolerance is universal (32°F is cold for everyone, regardless of where you live). This is backed by NPS park visitation data showing that cold suppresses outdoor activity far more than heat: January park visits are roughly 1/3 of summer peaks for year-round CONUS parks.

When temperatures drop below 50°F, a cold dampener reduces the overall score — clear skies and low humidity don't matter much when it's freezing outside. Overnight lows below freezing also carry a significant penalty.

Component Weights

• Temperature (30%) — Gaussian comfort curve centered at 75°F. Cold side drops faster than warm side (sigma 14 vs 15). Acclimation weight scales with temperature: 35% relative credit at 65°F+, dropping to 5% below 45°F. Overnight freeze penalty up to 25 points.
• Sky / Sunshine (20%) — Cloud cover percentage with a relative bonus for sunnier-than-normal days.
• Precipitation (18%) — Dry = 100, trace rain = 75, moderate rain = 40-60, heavy rain or ice = near 0.
• Humidity (14%) — Dew point comfort scale. Sweet spot 50-55°F dew point = 100. Above 70°F dew point (oppressive) drops sharply.
• Wind (10%) — Light breeze (3-8 mph) is ideal. Strong wind penalized, with a warm-weather breeze bonus and a cold+wind extra penalty.
• Visibility (4%) — Clear views > 10 miles = 100, fog penalized.
• UV Index (4%) — Moderate UV (3-5) is ideal, extreme UV penalized.

After the weighted sum, a cold dampener scales the overall score down when the high temperature is below 50°F (factor ranges from 1.0 at 50°F to 0.25 at 0°F). Severe weather events (tornado warnings, blizzards, etc.) apply additional penalties up to 50 points.

Example Scores

Calculated using the current scoring algorithm

Note: Minneapolis at 10°F scores 22 despite clear skies and no precipitation — the cold dampener ensures that freezing temperatures override good conditions in other categories. The 55°F warm spell scores 67: warmer than normal helps via acclimation, but the cold dampener still reduces the overall score since 55°F is borderline.

Population Weighting

Station scores are aggregated to state and national levels using county-centric population weighting. Each county's population (2024 Census estimates) is split among all weather stations within 75km using inverse-distance-squared weighting. This prevents dense-station metro areas from being over-counted — 10 stations near NYC split Manhattan's population rather than each claiming all of it.

The national index reflects how many Americans are experiencing pretty weather on any given day. Total station weights sum to ~337 million, closely matching the actual US population.

Data Sources

• NOAA ISD-Lite — Historical hourly observations (2018-present), the primary source for station baselines and historical scores
• Open-Meteo Forecast API — 16-day forecasts including UV index and visibility
• US Census Bureau — County population estimates and gazetteer coordinates for population weighting

Coverage

• ~1,700 ASOS/AWOS stations across the contiguous US
• Historical data from 2018 to present
• Daily forecast updates at 5:00 AM CT
• 48 states + DC covered