What it does
NASA POWER Weather Downloader requests fixed daily or hourly agrometeorological variables for one coordinate and date range. You can select the coordinate manually, on a map, through place search or with browser location, preview up to 100 returned rows and download the complete response as CSV.
The current app exports the variables returned by NASA POWER. It does not convert them to PCSE/WOFOST fields, fill missing values, calculate ET₀ or generate charts.
Before you start
- A network connection is required for NASA POWER and the external map services.
- Choose one coordinate in the latitude range
-90…90and longitude range-180…180. - Prepare an inclusive start and end date. Daily requests are limited to 3,660 days and hourly requests to 366 days.
- If using Get Current Location, allow browser geolocation or verify the approximate IP-based fallback coordinate carefully.
Quick workflow
- Choose Daily or Hourly in Time Scale. For hourly data, choose LST or UTC in Time Standard.
- Enter latitude and longitude, click the map, use Search, or select Get Current Location.
- Select Start Date and End Date.
- Select Download NASA Weather Data and monitor Status.
- Inspect the first returned rows in Data preview.
- Select Download CSV to save the complete returned table.
Controls & outputs
| Control or panel | Actual behavior |
|---|---|
| Time Scale | Chooses NASA POWER daily or hourly point data. |
| Time Standard | Sends LST or UTC with hourly requests. |
| Latitude / Longitude | Sets the request coordinate directly. Map clicks and location tools update these fields. |
| Search place or address / Search | Sends the query to Nominatim and uses the first result. Pressing Enter also starts a search. |
| Get Current Location | Requests browser geolocation; on unsupported, insecure, unavailable or timed-out cases it can try IP-based approximate location. |
| Download NASA Weather Data | Validates the inputs and requests the fixed parameter set. A later request cancels an active earlier request. |
| Data preview | Displays at most the first 100 records. |
| Download CSV | Downloads every parsed record, not just the preview. |
Daily parameters:
TOA_SW_DWN, ALLSKY_SFC_SW_DWN, T2M, T2M_MIN,
T2M_MAX, T2MDEW, WS2M, PRECTOTCORR
Hourly parameters:
T2M, T2MDEW, RH2M, WS10M, U10M, V10M, PS, PRECTOT
How it works
The app calls the NASA POWER point API with community AG, the chosen coordinate, inclusive date range and one fixed parameter list. Daily requests use the daily endpoint. Hourly requests use the hourly endpoint and include the selected time standard.
Returned parameter series are aligned by their date or hour keys and converted to rows. The preview renders the first 100 rows, while the CSV contains the full parsed response. Values are exported as returned; no statistical cleaning, interpolation or unit conversion is applied.
Data, privacy & external services
This workflow connects to several third parties:
| Service | Data sent or requested |
|---|---|
| NASA POWER | Coordinate, date range, time scale, time standard where applicable and parameter identifiers. |
| OpenStreetMap | Map tile requests for the visible area. |
| Nominatim | Text entered into place search. |
| ipapi.co | An IP-based approximate-location request after precise location cannot be used. |
| unpkg | Leaflet JavaScript and CSS required by the map. |
The downloaded records remain in browser memory until replaced or the page is closed. A temporary local URL is created for CSV download and revoked during cleanup.
Limitations
- NASA POWER is a gridded data product, not an on-site weather station measurement.
- Availability, units, missing-value flags and quality vary by variable, temporal product, place and period; check current POWER metadata before modelling.
- The app does not remove sentinel values or validate agronomic consistency.
- It provides one location per request and no monthly aggregation, batch processing, PCSE conversion, Excel export, charts or summary statistics.
- Map, search, approximate location and data retrieval depend on external availability, rate limits and browser network policy.
Troubleshooting
| Problem | What to check |
|---|---|
| Map does not load | Confirm Leaflet and OpenStreetMap resources are reachable. Coordinates can still be entered manually if the form is available. |
| Place search returns no result | Use a more specific query or enter coordinates manually. |
| Location is inaccurate | IP fallback is approximate; verify the marker and coordinates before requesting data. |
| Date validation fails | Enter both dates, keep start on or before end, and stay within the daily or hourly duration limit. |
| NASA POWER returns an error or no rows | Recheck coordinates and dates, shorten the range and retry after confirming POWER service availability. |
| The CSV contains missing or unusual values | Inspect the POWER metadata and clean or transform the exported data in your analysis workflow. |