Forecasts Precisely Where You Want Them

Search for a city, zip code, or latitude/longitude. Click any station on the map. Right-click on the map to Get Forecast Here.

Locations searched for by name are automatically remembered.

Multiple Forecasts

To give you a better sense of what the weather will be WeatherSpark can give you not one, but three forecasts (two outside the US), overlaid in the graphs.

Click the "Forecast" button just up right of the graphs to pick your primary forecast source and to enable displaying them all.

Only available on the dashboard / graphs pages, not on the simplified flash forecast or the regular html forecast pages.

Past Forecasts Subscription only

Compare old forecasts to what actually happened, to finally see how well the forecasters actually predict what's going to happen.

Click the little nubbins in the Histry title section to access past forecasts. You may need to zoom out or pan back in the history a bit to see them.

Map With Extended Historical Playback

Parts of this feature are subscription only

Play back recent radar and weather station data by just clicking the play button in the lower left corner of the map, or shift-click-and-drag in the graph to play back historical data.

This gives you amazing access to weather animations - just pan the graph to an interesting section such as an extended rainfall, and then shift-click at the start of the rain and drag to the end of the rain to see that section play out on the map.

There's a faint blue line in the graph indicating the point in time currently shown on the map.

To return to recent radar, click on the down arrow in the bottom right of the map to show the Animation Control Panel, then select the Now radio button.

You can also control playback speed, radar opacity, and looping in the Animation Control Panel.

Select the data shown using the button in the upper right corner of the map.

While other sites typically gives you two hours of recent radar, WeatherSpark gives you virtually unlimited playback range.

Dashboard With Everything In One Place

The WeatherSpark dashboard gives you unprecedented access to weather information in one place.

On the map you can immediately see if there's rain in the vicinity, and what the temperature is around you. In the graphs you get both an at-a-glance overview, as well as the most detailed weather information available on the planet.

Pan and zoom to access the extended forecast, recent history, or the typical weather for the location.

You can change the data shown for the weather stations by clicking the button in the upper right corner of the map.

Graphs With Full History and Records & Averages

The full history of the closest weather station, with its records and averages, are all integrated into the same graph that shows the forecast.

This allows you to view the specific weather for any particular point in the past. What was the weather when you were born?

You can also easily zoom out to get an overview of how the year has been so far, or what the typical year looks like.

Don't miss the quick time/zoom jump links just up left of the graphs.

The records and averages are computed from the history that we have available back to at most Jan 1st, 1973. Some stations have periods of spotty reporting, and for them we use a shorter history for this computation. We basically use as much as possible of the reliable information available.

The data is sampled on an hourly basis. Sometimes there are multiple reports per hour, and a station may experience an extreme temperature in between the reports that are actually kept. This can cause us to miss an extreme temperature. We are working to address this.

Compare Locations

Great for vacation planning! Compare up to four locations by holding down shift when clicking on the stations or when searching, or by clicking the "Compare"-button when searching.

Only available on the dashboard, not on e.g. the averages or forecast pages.

Full Screen Mode

To maximize the amount of weather information visible you can click the full screen link at the bottom of the screen.

This also disables sleep mode, so you can keep the app running like this in e.g. a public setting.

Graphs and Maps In Full Page Glory

The Dashboard, Graphs, and Maps tabs are all there to make the most of your viewing experience - pick the one that best shows what you're looking for.

Full Unit Customization

Conveniently switch between Celsius and Fahrenheit in the upper right corner. Click the down arrow to customize each graph individually.

Easily Save and Share the Current View

Click on the "Share" link in the upper right corner to get a link that takes you back to the exact view you're looking at. This link can be bookmarked or shared with others.

Global Warming Information

We've put together a resource dedicated to global warming.

Astronomy: Full Sun & Moon Information

Available as a separate graph, as optional information in the temperature graph, and over the map you always have detailed and clear information about the Sun and the Moon.

Location vs Weather Station

While we allow you to get a forecast for any location on earth, we can only show you history and records & averages for weather stations.

Therefore every location gets connected to the closest, best weather station (they are not all created equal).

This is visible on the map by the black line connecting the location to that weather station.

Save Your Settings

You can easily create a link that saves all your settings. Just click the "Save"-link in the top section, and then click bookmark.

Graphs

You can:

  1. Pan the graphs by clicking and dragging. Keyboard: left & right arrow keys.
  2. Zoom with the mouse wheel, and there are zoom shortcuts up left of the graph. Keyboard: up & down arrow keys.
  3. Pick the data series to show by clicking the "Graphs" button. Note the extra options available for some graphs.
  4. Switch between the available forecasts up right of the graph.

Hover Labels

For most series there is a little label shown if you hover the crosshair near a data point. This label can give a great little hint to what a given series is showing.

History, Forecast, and Averages

The graphs form a timeline starting with the history for the current weather station, continuing with the forecast for the current location, and finishing with the records & averages for the current weather station.

You can think of this as the past, the short-term predicted future, and then the most likely (or average) long term future.

In each section we try to show the most relevant information possible. For most series, there is a background with statistical information (averages, percentiles) to give you a feel for what normally happens. In some cases this didn't really work, and then this information is only shown in the Averages section.

Icons

The icons give a graphical representation of the weather for a day, week, month, or year depending on the zoom level.

If there is room, labels to the right of the icon indicate the high and low temperatures for the time interval. For the forecast the probability of precipitation, if any, is also shown.

Sun & Moon

On the lower zoom levels, the sun's and moon's elevations as well as rise and set times are shown, together with an icon depicting the current phase of the moon.

On higher zoom levels, the number of hours of sun in the day is shown instead and the moon information is hidden. The phase of the moon is shown up until the day zoom level.

Clouds

The graph shows the percentage of the sky covered by clouds. Higher numbers means more clouds and less sun.

Precipitation

Probability

History: The precipitation type reported by the weather station, if any, is shown as a bar graph. Since the y-axis has a max of 1 hour at the lowest zoom level and precipitation either happened or didn't happen in that hour, this can give the graph a somewhat boxy feel ("it's just bands of white and green!?"). For the higher zoom levels this gets aggregated, and the bars start having more nuance. So zoom out a little and you'll quickly see how it works.

Forecast: The probability that a given precipitation type will occur is shown as a line/area graph.

Averages: The percent of the time that it rains/snows/etc. So if it says 10% rain and you're on an hourly zoom level, then historically speaking, 10% of the hours had rain in them around that time of year.

Amount

On the hourly level, the amount is simply the amount of precipitation in that hour. When zooming out from the hourly level, the precipitation is summed becoming the precipitation over 4 hours, 1 day, 1 week, and so on, so it grows as you zoom out. The hover label tells you the interval for each point.

History: The liquid equivalent precipitation amount reported by the weather station, if any, is shown as a bar graph.

Forecast: The liquid equivalent precipitation amount is shown as a bar graph.

Averages: The average amount of liquid equivalent precipitation that falls in the zoom level's time interval, and associated statistical ranges (please see the Temperature graph for a description of the gray bands).

Rate

On the hourly level, the hourly rate is simply the amount of precipitation in that hour. When zooming out from the hourly level, the hourly rate is averaged for the hours that have precipitation in them, so its total range stays roughly the same as you zoom out.

History: The liquid equivalent precipitation rate reported by the weather station, if any, is shown as a bar graph.

Forecast: The liquid equivalent precipitation rate is shown as a bar graph.

Averages: The average rate of liquid equivalent precipitation in the zoom level's time interval, and associated statistical ranges (please see the Temperature graph for a description of the gray bands).

Amount vs Rate

The Amount graph answers the question "how much precipitation falls in place X over time Y?"

The Rate graph answers the question "when it rains, how much does it rain?"

Some places have never ending drizzle, whereas others have short but intense thunderstorms. Compare for example Seattle and Key West. Around the end of March they have very similar precipitation amounts (so they get the same number of inches of rain then), but in Key West the precipitation rate is about four times that in Seattle. When it rains, it pours, at least in Key West.

This is further underscored in the precipitation probability graph, where around the end of March it rains about 3% of the time in Key West, but a whopping 15% of the time in Seattle.

ColorTemp

History & Forecast show a 100% stacked bar chart, depicting the time the temperature spends in each temperature region.

This can be difficult to grasp at first, especially on the hourly level - try zooming out a bit and it should become more clear.

Averages show the same information but as a 100% stacked area chart.

Temperature

The historical temperature is shown with a thick black line, and the forecast is shown with a thick line in the selected forecast's color. The other forecasts are shown as faint lines.

The averages are overlaid throughout the entire timeline. The max and min temperature ever recorded for a given hour of the year are shown as faint gray lines (the "top" and "bottom" lines). The average temperature for that hour of the year is shown as a slightly stronger gray line (the "middle" line).

The gray bands in the center show what the usual temperature range is. The inner band shows the 25th to 75th percentile, and the outer band the 10th to 90th percentile.

The percentile numbers are computed using data from the adjacent days as well, so as to get sufficient statistical support for them. This means that it is possible for individual min/max values to be inside of the bands.

You can optionally show the dew point, the sun's elevation, and the current moon phase as overlays in this graph. Click on the Temperature graph label (up right inside the graph) to access the configuration menu.

For day+ zoom levels the daily high and low temperatures are shown as a bar graph instead. The gray bands are replaced by corresponding light red bands for the high temperature and light blue bands for the low temperature.

Dew Point

The dew point graph works much the same as the temperature graph, so please see the description for that graph.

For an explanation of what the dew point is, please see this wikipedia article.

You can optionally show the temperature overlaid in this graph.

Humidity

The humidity graph works much the same as the temperature graph, except that on the day+ zoom levels it stays a line graph, continuing to show the average relative humidity for the time interval in question.

Pressure

The pressure graph works much the same as the temperature graph, except that on the day+ zoom levels it stays a line graph, continuing to show the average air pressure for the time interval in question.

Note that NOAA's published forecasts don't include pressure.

Wind

The wind speed is the 2-minute average in the US and Canada and either 2- or 10-minute average outside North America.

Direction

The direction the wind is blowing is shown with little arrows, so wind coming from the north is shown with an arrow pointing down.

The time spent on average in any given wind direction is shown as a heatmap in the background.

Note that the size of the arrows is dependent on the zoom level, and is not proportional to the wind speed at that time.

Speed

The wind speed is shown in much the same way as the temperature, so please see that graph for an explanation for the gray ranges in the background.

This graph is shown in a logarithmic scale to allow for extreme winds without skewing the graph too much.

Icons

For an easier-to-read wind display, we also offer our take on the standard wind arrows. Unfortunately, these are not comparable across locations, so if you want to compare the wind conditions please use the other wind graphs.

Snow Depth

Some stations issue snow depth reports, typically every 6 hours when they do issue them.

To the extent such reports are available they are shown. Due to the poor reporting averages are not computed, and it is not forecasted by any of the forecasting agencies.

Visibility

Visibility is reported by some stations, typically with a max of 10 miles (16.1 km).

To the extent such reports are available they are shown. Due to the poor reporting averages are not computed, and it is not forecasted by any of the forecasting agencies.

Cloud Ceiling

Some stations report multiple cloud layers and a cloud ceiling.

The cloud ceiling is the lowest altitude with at least broken or overcast sky conditions.

A cloud layer is the altitude of the underside of a distinct layer of clouds.

To the extent such reports are available they are shown. Due to the poor reporting averages are not computed, and it is not forecasted by any of the forecasting agencies.