FREQUENTLY ASKED QUESTIONS
I am interested in hourly/daily/monthly/annual data for such-and-such location How much would it cost for this data?
The OCS and Mesonet data pricing policies are posted on the CIG website. The Mesonet data pricing policy is also posted on the Mesonet data website.
OCS staff have discretion on whether or not to charge for data. Generally, large datasets, especially Mesonet, will follow the pricing guidance, but for small requests (such as a few days from a single site), fees may be waived. OCS does not charge Oklahoma state or local governmental institutions for data, except for grant-funded research, in some instances. Specialized datasets that take staff time to develop may be charged at the Staff Services hourly rates.
If an invoice is required, use the OCS Data Request Database to list the fees. An invoice request will automatically be sent to the OCS Front Office when the request information is submitted.
I had some storm damage at my home. Can you help me document it for my insurance claim?
Check the NCDC Storm Events Database to see if official records for the month are archived yet. If not, check the NWS Forecast Office's Preliminary Storm Reports to see if they are posted. If not yet available, Check (1) Storm Prediction Center's Preliminary Storm Reports and (2) the National Weather Service Forecast Products search on CIG (search the resulting text file for the county). See "Documenting Storm Reports" for assistance.
How windy it was March 16 in Mustang? Were there any severe thunderstorms that month?
Maximum wind gust information for a day are on Mesonet Climatological Data (MCD) and f6 forms from the National Weather Service offices. Check all surrounding sites - both Mesonet and (if available), NWS sites. See Finding Daily or Monthly Data for assistance.
To determine the time of event, check Mesonet 5-minute observations using Mesotext or hourly observations from ASOS sites. See Pulling Hourly or Higher-Resolution Data for help on using mesotext or finding hourly ASOS observations.
Severe thunderstorm (wind) information is recorded on the NCDC Storm Events Database or NWS Forecast Office Preliminary Storm Reports. For recent information (within the past 4-5 months), see the Storm Prediction Center's preliminary storm reports, and on the NWS search engine. See "Documenting Storm Reports" for assistance.
How much rain did we get last night (week)? Did it cause any flooding?
For short-term, daily precipitation, check Mesonet Climatological Data and/or f6 forms from the National Weather Service offices. If the event happened more than a few months in the past, pull daily cooperative observer data to fill in holes. Pull multiple stations, if possible, because precipitation can be quite variable.
For multi-day accumulations, use the Recent Mesonet Rainfall table or http://www.mesonet.org/public/weathertrends.html (Hint: if you need 4-day accumulation, you can open the 72-hour frame in a new window and change rain72.hour.gif to rain96.hour.gif).
To check flooding, check either storm reports or use the NWS Search Engine to look for flood warnings issued for the time period / forecast office of responsibility.
See "Finding Daily or Monthly Data" or "Pulling Hourly or Higher-Resolution Data" for assistance with reported rainfall totals and "Documenting Storm Reports" for pulling storm reports or NWS warnings.
How hot was it today and did that break any records?
For the current day, check the maximum / minimum temperatures on either a Mesonet map, http://www.mesonet.org/public/statistics.html or from the National Weather Service (choose "Current Conditions / Present Weather" from the menu and then click on a station to pull up a time-series). For previous days, use the Mesonet Climatological Data forms and/or f6 forms from the NWS offices. See "Finding Daily or Monthly Data" for assistance with MCDs and f6 forms.
For records, pull a coop station's Monthly Climate Calendar to compare for the date. You can also use the Mesonet Extremes program on CIG /mesodata/Apps/Extremes/ to compare Mesonet observations to coop sites for a selected date. See "Climate Data Sources" for assistance with the Monthly Climate Calendar.
What was the hottest day this summer?
Determine the nearest station location for both First-Order stations and Mesonet sites. Check the National Weather Service f6 forms for each month during the summer (May-September; the highest could actually occur outside of June-July-August). At the bottom of each f6 form is a summary that includes the highest temperatue and date of occurrence. There could be multiple occurrences of the temperature, so record all dates during the period.
You can also search Mesonet data for values above some threshold. For example, select the nearest Mesonet station and time period. Use Maximum Temperature > or = to some value (say 95). The search will return all occurrences of maximum temperature reaching or exceeding the threshold. Note the highest and date of occurrence. Note that the Mesonet has more precision listed than the NWS observations, so round the numbers to the nearest full degree. For example, 98.3 would not be considered higher than 97.6 degrees by NWS standards - both would be recorded as 98 degrees and therefore both dates would have the highest temperature for the summer.
See "Finding Daily or Monthly Data" for assistance with f6 forms or Mesonet searches.
It has been really dry at my farm this spring. How bad is it?
Use Oklahoma Drought Update. Current season is on the top menu bar; past seasons are selectable under the 'past years' option on the left menu. Maps show point totals, departures, and percentages; tables show regional rankings, extremes, and historical context.
Recent Mesonet Rainfall provides Mesonet-station rainfall totals for periods ranging from 7 to 90 days. Station totals can be compared to nearby normals.
See Mesonet / Recent Mesonet Rainfall in "Finding Daily or Monthly Data" and "Climate Data Sources" for assistance with normals.
What was the weather like in June 1954? How does that compare to this month?
Look at Cooperative Observer Data, A Month in Time, for a nearby station. For the current month, use either a Mesonet Climatological Data (MCD) summary or an f6 forms from a nearby NWS / ASOS observing site. If comparing to extremes, look up the corresponding station's daily and monthly extremes in the Monthly Climate Calenar. See "Finding Daily or Monthly Data" for assistance on monthly observations and "Climate Data Sources" for assistance with extremes.
I am looking at possible pesticide drift. Can you tell me the wind conditions at my ranch on some selected dates/times?
For daily periods, check Mesonet observations using either Mesonet Climatological Data (MCDs) or the Daily Data Retrieval for an extended period (pull both primary and secondary wind directions and frequencies). If the site is near a federal observing site, check the f6 forms. For higher time resolution, use mesotext or NWS hourly observations (decoded metars). See "Finding Daily or Monthly Data" for finding daily data or "Pulling Hourly or Higher-Resolution Data" in for assistance with mesotext or NWS ASOS observations.
Can you tell me when the first freeze occurs at my farm? What was the earliest date?
Maps of average dates of first freeze are on the OCS Climate Data pages under First/Last Freeze Days. The maps provide median dates for first freeze (32 degrees low temperautre) or hard freeze (28 degrees). Other maps provide a sense of ranges, from earliest to latest, with a range of probabilities of occurrence (for example, First Freeze Autumn 10% shows the date at which 10% of years experienced a freeze). Extremes are unique events, and planning for the earliest date may not be the best strategy. Generally, for planning purposes, a freeze can be expected within the 20% - 80% range, although the 10%-90% range provided in the maps can be used as a planning tool.
Station-by-station listings of freeze/frost thresholds have been calculated by NCDC in their CLIM20, Supplement 1 publication, "Freeze/Frost data for the U.S.", linked from the cig website in the Winter Weather Section. A printed copy is kept in the OCS library (blue book). An updated publication, based on 1971-2000 data, is expected in Summer 2004 and will be posted on the NCDC normals website.
Freeze/frost tables can also be generated from the scs program on cig /ocsdata/coop/apps/. The tables have been produced for selected stations in the OCS County Climatologies series (documents on cig in /ocsdata/County Climatologies/) and will be produced for about 150 long-term stations.
Use the Monthly Climate Calendar for a selected coop site to determine the earliest (or latest) daily occurrence.
See "Climate Data Sources" for locating NCDC normals publications and for retrieving Monthly Climate Calendars.
Is it possible to get data on the average prevailing wind direction by month for a given weather station?
Wind roses and frequency distribution tables are in the CD Atlas of Oklahoma Climate. At this time, only period-of-record annual tables and wind roses are available, but monthly or seasonal data can be generated on an as-needed basis (a fee may apply). See "Climate Data Sources" for assistance with the CD Atlas.
For wind data in a particular month (i.e., May 1999), use Mesonet Climatological Data or f6 forms from NWS observing sites (whichever is closest). See "Finding Daily or Monthly Data" for accessing MCDs and f6 forms.
If the data are for an analysis of potential wind energy, refer to the Oklahoma Wind Power Initiative (see FAQ below on "I want to put a windmill at my house").
I'm planning a new development and need to build a retention pond that will hold the 50-year rainfall runoff. How much rain would that be?
Check CLIMOCS for the nearest station to find the maximum daily rainfall to provide a benchmark. Then, interpolate values from the Rainfall-Runoff Maps publication for Oklahoma (USGS 1998 - large set of maps in the OCS Front Office) for the location. Provide rainfall values for all time periods published. Also, the ESE Precipitation Databook publication (thick white & blue book in the OCS library) has peak rainfall intensity tables for some locations in Oklahoma. See "Climate Data Sources" for assistance on pulling CLIMOCS.
I am designing a wastewater lagoon for Crowder, OK. I need to know the average monthly rainfall and pan evaporation for Crowder. Also, can you give me 80th percentile values for rainfall?
For average rainfall for a location, use either NCDC monthly normals, CLIM 81, and/or CLIMOCS. See "Climate Data Sources" for finding NCDC normals or using CLIMOCS.
Pan evaporation data can be generated from cooperative observer data, but only for about 28 stations statewide. Ask CIG staff for assistance.
Modelled evapotranspiration can be generated from the Mesonet's ET model Ask CIG staff for assistance.
To determine rainfall percentiles, pull Crowder's (or nearest long-term cooperative observer site) monthly rainfall data using readcoop on cig /ocsdata/coop/apps/. Copy the monthly data into Excel (or other spreadsheet) and sort by month. Then sort values for the requested month from lowest to highest. Determine the number of valid observations (years with complete data) and multiply by 0.8. The resulting number is the element of the array of valid observations corresponding to the 80th percentile.
I'm doing a science fair project on changes in Oklahoma's climate. Can you give me monthly or annual temperature / rainfall data over a long period?
Monthly and annual temperature and precipitation maps, and climate division graphs are on the CD Atlas of Oklahoma Climate in the "Oklahoma's Climate History" section - see Historical Temperature and Precipitation by Month for trends, by climate division or state overall, or Month-by-Month Rainfall since 1893.
Individual station data can be retrieved from cooperative observer data, using either the Timeseries for daily data or Readcoop to pull monthly-summarized observations.
See "Finding Daily or Monthly Data" for assistance on pulling cooperative observer data or "Climate Data Sources" for other sources of climate information.
I'm trying to figure out whether or not to grow grapes in Oklahoma. Can you tell me how long growing seasons are, how dry it is in summertime, and how cold it gets in winter?
Oklahoma's climate is surprising good for growing grapes. For the location in which the individual is wanting to grow grapes, look up freeze/frost information, monthly normal precipitation, and monthly normal and extreme temperatures.
For tips on pulling freeze/frost information, see "Can you tell me when the first freeze occurs at my farm?" in this FAQ (above).
See NCDC normals for monhtly-average precipitation, maximum, and minimum temperature. For temperature extremes, use CLIMOCS. See "Climate Data Sources" for locating NCDC normals publications and for retrieving CLIMOCS.
The indiviudal may want likely temperatures in addition to extremes. Exceedence values - roughly the expected range of temperatures, by month, are included in the County Climate summaries on cig /ocsdata/County Climatoliges/ and can be generated for any long-term cooperative observer station using the scs program on cig /ocsdata/coop/apps/. See "Climate Data Sources" for more information on county climatologies.
I want to put in a windmill at my house. Is it windy enough to make it worthwhile?
Mean wind speeds can be found in the CD Atlas of Oklahoma Climate or in the County Climate summaries on cig /ocsdata/County Climatologies/.
For analysis of wind generation capability, see the Oklahoma Wind Power Initiative (OWPI) website, http://www.ocgi.okstate.edu/owpi/. The OK Wind Resource section has maps of wind power density and "OWPI Wind Climatology Reports" for selected Mesonet stations (mostly west of I-35).
See "Climate Data Sources" for assistance with the CD Atlas.
When is sunrise/sunset/moonrise/moonset/fullmoon/newmoon/etc?
Astronomical data are on the U.S. Naval Observatory website.