IMGW User Guide

Comprehensive user guide for the IMGW Explorer, detailing how to navigate the map, filter Polish stations, and visualize high-resolution weather data.

Access the Application: Return to Explorer

1. Introduction

The IMGW Explorer is an interactive dashboard for exploring historical and recent weather data from the Polish Institute of Meteorology and Water Management (IMGW-PIB). It allows you to visualize meteorological records from synoptic and climatological stations across Poland. Data is available in three resolutions: Hourly, Daily, and Monthly.

1.1 Station Types

The explorer includes two main types of observation stations:

• Synoptic Stations: Premium stations that collect the most comprehensive data, including detailed wind observations, cloud cover, visibility, weather codes, and atmospheric pressure.
• Climatological Stations: A broader network that provides core parameters like temperature, precipitation, and snow measurements, with varying levels of instrumentation.

2. Global Navigation (Sidebar)

The sidebar on the left controls the global view of the application.

• Station Count: Shows the number of stations matching your current filters.
• Find Station: A searchable dropdown to quickly locate a specific station by name.
• Temporal Resolution: Toggle between Hourly, Daily, and Monthly data modes. This filters the available stations and determines the granularity of the data visualized.
• Date Range: Select a date range for the data request.
  • Note: The application automatically limits the date range to prevent overloading (e.g., ~1 year for daily data, ~3 months for hourly).

3. Main Navigation Tabs

The application features three main tabs at the top:

Map View

Map View

The default view is an interactive map showing available IMGW weather stations across Poland.

• Markers: Blue dots represent available stations.
• Selection: Click any marker to highlight the station and view its summary popup.
• Home Button: A “Home” icon resets the view to the full extent of Poland.
• Layer Control: Switch between different basemaps (Positron, Bright, Satellite) and toggle labels on/off.

Stations Info

Stations Info

A tabular listing of all filtered stations. This view is useful for browsing the full station catalog.

• Double-Click: Double-click any row to fetch that station’s data and navigate directly to the Dashboard.

Dashboard

Dashboard Plots

The Dashboard displays detailed data for a selected station. It becomes active after selecting a station from the map or table.

Dashboard Sub-Tabs

1. Plots: Interactive visualizations for different weather parameters:

   • Temperature: Timeline of mean, maximum, and minimum temperatures.
   • Precipitation: Bar charts of precipitation accumulation.
   • Wind: Wind speed timeline and wind rose (for hourly data).
   • Pressure: Station-level and sea-level pressure trends.
   • Humidity: Relative humidity trends.
   • Sunshine: Sunshine duration (where available).
   • Snow: Snow depth and fresh snowfall (where available).

2. Data: Provides raw data access for the selected station and period.

   

   Dashboard Data

   • The table displays the parsed and translated data.
   • Quality flags are integrated into the displayed values.
   • Export Excel: Use the download button to save the currently loaded dataset as an Excel file.

4. Parameter Reference

The following tables list key parameters available in the IMGW Explorer for each resolution. Not all stations measure all parameters.

Hourly Parameters

[!NOTE] All timestamps for Hourly resolution are in Central European Time (CET/CEST).

Column Name	Definition	Unit
Temp	Air Temperature	°C
Dew Point	Dew Point Temperature	°C
Relative Humidity	Relative Humidity	%
Wind Speed	Mean Wind Speed	m/s
Wind Direction	Wind Direction	°
Wind Gust	Maximum Wind Gust	m/s
Station Pressure	Station-Level Pressure	hPa
Sea Level Pressure	Sea-Level Pressure	hPa
Precipitation 6h	6-Hour Precipitation Total	mm
Snow Depth	Snow Depth on Ground	cm
Sunshine	Sunshine Duration	h
Cloud Cover	Total Cloud Cover	oktas
Visibility	Horizontal Visibility	km

Daily Parameters

Column Name	Definition	Unit
Mean Daily Temp	Daily Mean Temperature	°C
Max Temp	Daily Maximum Temperature	°C
Min Temp	Daily Minimum Temperature	°C
Daily Precip	Total Daily Precipitation	mm
Mean Wind Speed	Daily Mean Wind Speed	m/s
Max Gust	Maximum Wind Gust	m/s
Mean Rel Humidity	Mean Relative Humidity	%
Snow Depth	Snow Depth on Ground	cm
Fresh Snow	Fresh Snow Depth	cm
Sunshine	Total Sunshine Duration	h

Monthly Parameters

Column Name	Definition	Unit
Mean Monthly Temp	Monthly Mean Temperature	°C
Max Monthly Temp	Monthly Maximum Temperature	°C
Min Monthly Temp	Monthly Minimum Temperature	°C
Monthly Precip	Total Monthly Precipitation	mm
Mean Wind Speed	Monthly Mean Wind Speed	m/s
Monthly Sunshine	Total Sunshine Duration	h
Snow Days	Number of Days with Snow Cover	days

5. Quality Flags

The IMGW raw data includes status flags indicating measurement quality:

• Standard measurement (no flag)
• [8]: No observations performed
• 9 → 0: “No phenomena” flag (e.g., no precipitation occurred)
• Special values for snow depth: 997 = less than 0.5 cm, 998 = patchy, 999 = unmeasurable

In the data table, these flags are integrated directly into the displayed values or shown as muted superscripts.

7. Common Use Cases

Beyond browsing raw observations, the IMGW Explorer supports a range of practical and analytical workflows:

• Climate Trend Analysis: Select a station with a long record (e.g., Warszawa-Okęcie or Kraków-Balice) and compare monthly mean temperatures across decades to identify warming trends, shifting frost dates, or changes in precipitation seasonality.
• Agricultural Planning: Farmers and agronomists can examine daily temperature and precipitation data to determine optimum sowing windows, estimate growing degree-days, or assess drought risk during critical growth phases.
• Flood Event Investigation: Switch to hourly resolution and examine precipitation intensity during known flood events on the Vistula or Oder river basins. Combine this with wind and pressure data to reconstruct the synoptic situation that triggered the event.
• Renewable Energy Assessment: Use multi-year daily or hourly wind speed records to evaluate wind energy potential at locations near IMGW synoptic stations. Sunshine-duration data can similarly support preliminary solar energy feasibility studies.
• Education & Research: University lecturers and students can use the explorer as a teaching tool — for example, to illustrate the concept of temperature inversions, foehn effects in the Tatra foothills, or the urban heat-island effect by comparing city stations against nearby rural ones.

8. Data Source

Original data is sourced from the IMGW-PIB open data portal.

• Source URL: IMGW Public Data
• Metadata: Station coordinates and operational information are derived from the IMGW metadata catalog.