C4B and Weather Spark at a glance
| Aspect | C4B | Weather Spark |
|---|---|---|
| Type | Web app, in the browser | Consumer climate website |
| Price | Free plan; paid plans from €59/month (cancellation takes effect after 12 billing cycles) or €599/year, with a 7-day free trial | Free to browse; paid data download plans |
| Choosing the location | Search an address or click the map; no weather file needed | Search for a named place |
| Weather data | Nearest weather station file (Climate.OneBuilding.Org, usually TMYx) plus, in projects, site-specific reanalysis (ERA5 / ERA5-Land, CERRA, NORA3) at the exact coordinates | NASA MERRA-2 reanalysis and nearby airport stations, 1980 to 2016 |
| Future climate | SSP1-1.9 to SSP5-8.5, any year from 2025 to 2100, in projects on paid plans | Not stated on the pages we reviewed |
| Outdoor comfort | UTCI outdoor comfort, including on the Free plan | Not stated on the pages we reviewed |
| Energy analysis | Preliminary hourly energy balance; orientation and aspect-ratio optimization in projects on paid plans | Solar energy overview |
| Outputs | Interactive charts; written readings on most charts in projects and a PDF report on paid plans; EPW downloads on Technical and Enterprise | Web charts; paid data downloads and chart licences |
Where Weather Spark is strong
- Free to browse, instant and very readable for almost any place.
- Covers many variables with clear seasonal charts.
- Month-by-month views of temperature, cloud cover, precipitation and wind for each place, and a chart of average temperature by hour of the day through the year.
Where C4B takes a different approach
- Built for building design: psychrometric chart, passive strategies, UTCI outdoor comfort, wind roses, sun path and energy balance.
- Always shows the nearest weather station's typical year, and in projects builds the site's typical year from 15 complete years of reanalysis (ERA5 / ERA5-Land, with CERRA and NORA3 regionally; 2011 to 2025, or 2006 to 2020 where CERRA is used).
- Adds Köppen-Geiger zones to 2100, future climate scenarios and a PDF report.
Weather Spark may suit you better if
- You want a quick, free sense of a place's typical weather through the year.
C4B may suit you better if
- You are designing a building or outdoor space and need design-specific analyses.
- You need recent data, future climate or a report you can share with a client.
See your site's climate before design begins
Pin any location and get climate, comfort and preliminary energy insight your whole team can read. Start with a 7-day free trial, or book a 30-minute demo.
Frequently asked questions
Is Weather Spark data suitable for building design?
Weather Spark is designed for general climate overviews, and its own pages describe its data period (1980 to 2016) and grid resolution. Building design usually needs hourly design analyses such as comfort, wind and psychrometrics.
What data does Weather Spark use?
Its climate reports combine NASA MERRA-2 reanalysis (on a grid of about 50 km) with temperature records from nearby airport stations, for 1980 to 2016.
What does C4B show that Weather Spark does not?
Design analyses such as the psychrometric chart and passive strategies, UTCI outdoor comfort, climate zones to 2100, future climate scenarios and a preliminary energy balance.
Is C4B free?
C4B has a free plan with climate and energy analyses on weather-station data, and paid plans from €59 per month (monthly plans are cancelled 12 billing cycles after notice) with a 7-day free trial.
Sources
Information about Weather Spark comes from its official website and documentation, checked on 18 September 2026. Products change, so check the official site for the latest details. Weather Spark belongs to Cedar Lake Ventures, Inc.; C4B is not affiliated with or endorsed by them.
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