Climate Analyzer

Upload .epw file

You can upload and visualize more than one climate (EPW) file at a time — select multiple files at once, or upload them one after another. Each city appears as its own card above and can be compared side by side across every tab.

Climate Analyzer User Guide

1. Upload weather files

Upload one or more EPW files at once, or add them one after another. The program reads hourly dry-bulb temperature, relative humidity, wind direction, wind speed, solar radiation, and sky-cover fields. Each city appears as its own card and can be compared side by side across every tab.
Use the SI/IP toggle at the top to change displayed units (IP is the default). PMV and PPD remain dimensionless/percent values regardless of the unit setting.

2. Read each tab

Temperature: hourly and monthly dry-bulb temperature (now labeled by month), a Monthly Temperature Box Diagram (2.5th-97.5th percentile band, mean, and min/max whiskers), and an Average Daily Temperature Profile by Month diagram (each month's 24-hour cycle drawn within its own band).
Humidity: the same pairing for relative humidity - hourly/monthly charts plus a Monthly Relative Humidity Box Diagram and an Average Daily Relative Humidity Profile by Month diagram.
Wind Speed: annual, seasonal, and monthly wind-rose summaries.
Solar Radiation: compares monthly GHI, DNI, DHI, sky cover, and likely shading-needed hours.
Psychrometric Chart: plots monthly thermal-humidity profiles against the ASHRAE 55 comfort zone, lets you test passive strategies against an adjusted comfort polygon, and includes a table showing the percentage of the year within the comfort zone, broken down strategy by strategy, ending in a combined total.
Thermal Comfort: screening-level PMV/PPD, PET, UTCI, and SET* estimates, an annual UTCI stress-category chart, and monthly comfortable/no-stress hours - each with a short definition of the index or category shown.
Design Strategies: screens annual hours for broad passive and active strategy categories; when more than one city is loaded, an additional comparison table breaks every strategy category down city by city. The tab also links each strategy category to related design guidance in the 2030 Palette, with full citations.

Because two different tabs use two different comfort definitions - the ASHRAE 55 dry-bulb/humidity box on the Psychrometric tab versus the broader PMV/UTCI-based screen used elsewhere - their percentages will not always match. This is expected; each is explained where it appears.

3. Export report

Click Save Climate Analysis Report after uploading files. The exported HTML report is written as a learning and analytical tool: it opens with a glossary of terms and chart-reading guidance, then walks through every chart in the app for each city (temperature and humidity, including the box and daily-profile diagrams; the psychrometric summary and comfort-zone breakdown; solar radiation and shading; wind roses; and thermal comfort indices), each followed by a short discussion of what it shows and why it matters for design - plus a cross-city comparison section when multiple climates are loaded, and a 2030 Palette appendix with citations.

Thermal comfort indices and strategy screens are simplified screening estimates. Use validated tools for compliance, medical, or publication-grade analysis.

Psychrometric Strategy Hours

Thermal comfort definition used in these pie charts: each hour is sorted into exactly one dominant strategy category, checked in priority order. An hour is labeled "Thermal Comfort" either because it directly matches the ASHRAE 55 box (20-26°C, 30-65% RH), or - as a catch-all - because its temperature is 20-26°C and it didn't match any more specific strategy (e.g. natural ventilation, humidification). This second path means the "Thermal Comfort" share here can run higher than the strict comfort-zone percentage on the Psychrometric Chart tab.

Related Passive Strategies in the 2030 Palette

The 2030 Palette is a free, searchable library of climate-responsive design strategies ("swatches"), published by Architecture 2030 and organized across five scales — Region, City/Town, District, Site, and Building. The categories screened in the pie charts above map most closely to the Palette's Building-scale swatches, linked below for design guidance, precedent images, and technical detail beyond the screening-level percentages shown here. Rows are ordered by how many hours of the year each strategy applies, averaged across the uploaded climate file(s).

Strategy category (this tool)	Avg. % of year	Related 2030 Palette Building swatch(es)

The Palette also documents Building-scale strategies this tool doesn't directly screen — such as daylighting (Side Daylighting, Top Daylighting, Clerestories and Skylights) and building-integrated renewables (Building-Integrated Photovoltaics) — worth reviewing directly on the Palette site.

Citations

Architecture 2030. (n.d.). 2030 Palette: Building [Overview page]. Retrieved July 7, 2026, from https://2030palette.org/building/
Architecture 2030. (2017, April 3). Shading Devices. 2030 Palette. https://2030palette.org/shading-devices/
Architecture 2030. (2017, April 3). East/West Shading. 2030 Palette. https://2030palette.org/eastwest-shading/
Architecture 2030. (2016, December 15). Solar Shading. 2030 Palette. https://2030palette.org/solar-shading/
Architecture 2030. (2017, April 3). Direct Gain: Heat Storage. 2030 Palette. https://2030palette.org/direct-gain-heat-storage/
Architecture 2030. (2017, April 3). Thermal Storage Wall. 2030 Palette. https://2030palette.org/thermal-storage-wall/
Architecture 2030. (2017, April 3). Earth Sheltering. 2030 Palette. https://2030palette.org/earth-sheltering/
Architecture 2030. (2017, April 3). Night Vent Cooling. 2030 Palette. https://2030palette.org/night-vent-cooling/
Architecture 2030. (2017, April 3). Evaporative Cooling Towers. 2030 Palette. https://2030palette.org/evaporative-cooling-towers/
Architecture 2030. (2017, April 3). Cross Ventilation. 2030 Palette. https://2030palette.org/cross-ventilation/
Architecture 2030. (2017, April 3). Stack Ventilation. 2030 Palette. https://2030palette.org/stack-ventilation/
Architecture 2030. (2017, April 3). Direct Gain: Glazing. 2030 Palette. https://2030palette.org/direct-gain-glazing/
Architecture 2030. (2017, April 3). Indirect Gain: Sunspace. 2030 Palette. https://2030palette.org/indirect-gain-sunspace/
Architecture 2030. (2017, April 3). Solar Greenhouse. 2030 Palette. https://2030palette.org/solar-greenhouse/
Architecture 2030. (2017, April 3). Form For Heating. 2030 Palette. https://2030palette.org/form-for-heating/
Architecture 2030. (2017, April 3). Form For Cooling. 2030 Palette. https://2030palette.org/form-for-cooling/
Architecture 2030. (2017, April 3). Cool Roof. 2030 Palette. https://2030palette.org/cool-roof/
Architecture 2030. (2017, April 3). Green Roof. 2030 Palette. https://2030palette.org/green-roof/
Architecture 2030. (2017, April 3). Side Daylighting. 2030 Palette. https://2030palette.org/side-daylighting/
Architecture 2030. (2017, April 3). Top Daylighting. 2030 Palette. https://2030palette.org/top-daylighting/
Architecture 2030. (2017, April 3). Clerestories and Skylights. 2030 Palette. https://2030palette.org/clerestories-and-skylights/
Architecture 2030. (2024, October 15). Building-Integrated Photovoltaics. 2030 Palette. https://2030palette.org/building-integrated-photovoltaics/

Psychrometric Chart

Dynamic Comfort Zone (PMV -0.5 to +0.5)

Metabolic rate (met)

1.1 met - Standing, light activity

Sleeping (0.7)Seated (1.0)Standing (1.2)Walking (2.0)

Clothing level (clo)

0.70 clo - Typical indoor clothing

Nude (0.0)Light (0.5)Indoor (0.7)Suit (1.0)Winter (1.5)

Thermal comfort zone shown on this chart (ASHRAE 55 screening approximation): operative temperature roughly 20-27°C (68-81°F) and relative humidity between 30-65%, plotted as the winter and summer comfort zone outlines below. Operative temperature is approximated as the average of dry-bulb air temperature and mean radiant temperature.

Temperature Analysis

Hourly Dry-Bulb Temperature (°C)

Average Monthly Temperature (°C)

Average Daily Temperature Profile by Month (°C)

Each month's average 24-hour temperature cycle is drawn within its own band, from 00:00 at the left edge of the band to 24:00 at the right edge.

Monthly Temperature Box Diagram (°C)

Box: 95% of hourly values for the month (2.5th-97.5th percentile) · Line inside box: monthly mean · Whiskers: monthly min and max.

Humidity Analysis

Hourly Relative Humidity (%)

Average Monthly Relative Humidity (%)

Average Daily Relative Humidity Profile by Month (%)

Each month's average 24-hour relative humidity cycle is drawn within its own band, from 00:00 at the left edge of the band to 24:00 at the right edge.

Monthly Relative Humidity Box Diagram (%)

Box: 95% of hourly values for the month (2.5th-97.5th percentile) · Line inside box: monthly mean · Whiskers: monthly min and max.

Wind Speed and Direction Analysis

Annual Wind Rose

Seasonal Wind Roses

Monthly Wind Roses

Solar Radiation and Cloud Cover Analysis

Monthly Solar Radiation Totals (kWh/m²)

Monthly Average Cloud Cover (tenths)

Monthly Time-of-Day Shading Need

Thermal Comfort Analysis

Clothing Level

Summer clothing (applies to June, July, August only)

0.50 clo - Light summer clothing

Nude (0.0)Light (0.5)Indoor (0.7)Suit (1.0)Winter (1.5)

Transitional clothing (applies to March-May and September-November only)

0.70 clo - Typical indoor clothing

Nude (0.0)Light (0.5)Indoor (0.7)Suit (1.0)Winter (1.5)

Winter clothing (applies to December, January, February only)

1.00 clo - Business suit / light jacket

Nude (0.0)Light (0.5)Indoor (0.7)Suit (1.0)Winter (1.5)

Most Effective Passive Strategies for Thermal Comfort Adjustment

Winter months (Dec/Jan/Feb)

Upload and select a city to show strategy options.

Summer months (Jun/Jul/Aug)

Upload and select a city to show strategy options.

Transitional months (Mar-May, Sep-Nov)

Upload and select a city to show strategy options.

Selected strategies generate adjusted screening-level PMV/PPD, PET, UTCI, SET*, and comfort-hour estimates for comparison with the original EPW climate data. Winter-month strategies only affect December/January/February; summer-month strategies only affect June/July/August; transitional-month strategies only affect the March-May and September-November shoulder months. Within each section, strategies are ranked #1, #2, ... by how often they actually dominate during that specific season for this climate, most significant first. A strategy tagged All-season ranks among the effective strategies in all three seasons - worth prioritizing first since it pays off year-round.

Monthly Mean PMV and PPD

Light green band indicates PMV thermal comfort range (-0.5 to +0.5). PMV (Predicted Mean Vote) is a -3 (cold) to +3 (hot) estimate of the average occupant's thermal sensation, with 0 as neutral. PPD (Predicted Percentage Dissatisfied) is the estimated % of occupants likely to feel too warm or too cool at that PMV; PPD is always at least ~5% even at PMV = 0.

Monthly Outdoor Thermal Indices (°C)

PET (Physiological Equivalent Temperature), UTCI (Universal Thermal Climate Index), and SET* (Standard Effective Temperature) each fold air temperature, humidity, wind, and radiation into one "feels-like" equivalent temperature, using different reference models - so they can disagree by a few degrees for the same hour.

Annual UTCI Stress Category Hours

UTCI stress categories (dry-bulb-equivalent °C): <-40 extreme cold · -40 to -27 very strong cold · -27 to -13 strong cold · -13 to 0 moderate cold · 0 to 9 slight cold · 9-26 no thermal stress · 26-32 moderate heat · 32-38 strong heat · 38-46 very strong heat · >46 extreme heat stress.

Monthly Thermal Comfortable Hours

An hour counts as comfortable/no-stress here if PMV is within ±0.5 or UTCI falls in the 9-26°C no-thermal-stress range - whichever condition is met. This differs from the ASHRAE 55 dry-bulb/humidity box used on the Psychrometric Chart tab.