Washington: Today - Cloudy and cooler with a 50 percent chance of rain through tonight, high near 85, low in the 70s. Winds will be northwesterly at 10 mph shifting to the northeast by nightfall. Thursday - Cloudy, high in the 80s.

Maryland and Virginia: Today - Mostly cloudy and cooler with a good chance of rain through tonight, highs in the 70s to low 80s, low in the 60s. Thursday - Cloudy, rain possibly continuing, high in the 70s.

Extended Area Forecast for Friday through Sunday - Partly cloudy with a chance of showers Friday, becoming warmer and more humid. Highs will average in the 80s, lows in 60s to low 70s. Normal Washington temperatures are a high of 84 and a low of 65.

Lower Potomac and Chesapeake Bay - Mostly cloudy with a chance of rain. Visibility will be 1 to 3 miles in haze, less than 1 mile in precipitation. Winds will be light and variable. Waves will average 1 foot or less.

Atlantic Ocean Beaches from Maryland to North Carolina: Today and Thursday - Partly cloudy, warm and humid with a chance of thunderstorms, high in the 80s. Water temperatures will be in the upper 70s to near 80.

Atlantic Ocean Beaches of New Jersey and Delaware: Today and Thursday - Mostly cloudy and cooler with a good chance of rain, high in the 70s. Water temperatures will be in the mid 70s.

The national weather forecast for today - Rain and thunderstorms will extend from the lower Mississippi Valley to the Atlantic from northern Florida to Delaware. Scattered thundershowers will range from portions of the plateau to the lower Mississippi Valley, through the lower Great Lakes and from Washington state into Montana. Skies will be mostly sunny from California across the central Rockies and the central and northern Plains into the upper Great Lakes and over much of New England. Temperatures will be mild from the Pacific Northwest through the northern half of the Rockies, across the Plains, the Mississippi Valley, and into the lower Ohio Valley, and upper Great Lakes. Much of the remainder of the nation can expect warm temperatures.

Almanac Data for today: The sun rises 6:35 a.m., sets 7:42 p.m.; moon rises 3:46 a.m., sets 5:53 p.m. Tides: high 6:34 a.m. and 7:06 p.m., low 1:12 p.m. High and low tides at the following locations may be obtained by subtracting the hours indicated from the hours above. Annapolis (3 1/4), Bloody Point Lighthouse (4 1/2), Deale, Md. (4 1/2), Colonial Beach (5 1/2), Norfolk (1), Virginia Beach (3 1/4), Solomons Island (6 1/4), Point Lookout (7).

Pollen Count: 24-Ragweed (a reading of more than 7 is considered to be undesirable).

The Council of Governments' Air Quality Index for yesterday showed the high reading in the Washington area during the 3 p.m. period was 50 for the pollutant, photo-chemical oxidants. Index values between 50 and 99 indicate unhealthy air quality. When the index exceed 100 and air is considered very unhealthy and individuals with lung, heart and eye ailments are urged to restrict their activity. The forecast for today indicates that the air quality will deteriorate.

The National Weather Service forecasts the Potomac River Stage at Little Falls should fall to near 3.1 feet today.

Washington data for yesterday: Highest temperature since midnight yesterday, 93 degrees at 3:10 p.m. Lowest temperature since midnight, 76 degrees at 6:30 a.m. Excess of temperature since Aug. 1, 127 degrees. Deficiency of temperature since Jan. 1, 14 degrees. Record high temperature for today, 99 degrees in 1953. Record low temperature for today, 50 degrees in 1896. Relative humidity: maximum, 91 percent at 7 a.m.; minimum, 51 percent at 3 p.m. 24 hour precipitation, none. Deficiency of precipitation since Aug. 1, 60 inches. Excess of precipitation since Jan 1, 2.09 inches. Highest observed wind since 8 a.m., 15 miles per hour from the west at 11:53 a.m. Peak gust since 8 a.m., 23 miles per hour from the west at 12:33 p.m. Local Temps. Humidity(TABLE) Time(COLUMN)T.(COLUMN)H. 12 midnite(COLUMN)82(COLUMN)75 1 a.m.(COLUMN)81(COLUMN)77 2 a.m.(COLUMN)80(COLUMN)80 3 a.m.(COLUMN)79(COLUMN)82 4 a.m.(COLUMN)78(COLUMN)85 5 a.m.(COLUMN)78(COLUMN)85 6 a.m.(COLUMN)77(COLUMN)88 7 a.m.(COLUMN)76(COLUMN)91 8 a.m.(COLUMN)78(COLUMN)85 9 a.m.(COLUMN)84(COLUMN)70 10 a.m.(COLUMN)87(COLUMN)64 11 a.m.(COLUMN)89(COLUMN)60 12 noon(COLUMN)91(COLUMN)56 1 p.m.(COLUMN)91(COLUMN)52 2 p.m.(COLUMN)91(COLUMN)52 3 p.m.(COLUMN)92(COLUMN)51 4 p.m.(COLUMN)92(COLUMN)51 5p.m.(COLUMN)92(COLUMN)52 6 p.m.(COLUMN)91(COLUMN)51 7 p.m.(COLUMN)89(COLUMN)54(END TABLE) Temperatures ending 8 a.m. (EDT) yesterday:(TABLE) City(COLUMN)H.(COLUMN)L. Albuquerque(COLUMN)91(COLUMN)66 Amarillo(COLUMN)86(COLUMN)60 Anchorage(COLUMN)62(COLUMN)44 Asheville(COLUMN)85(COLUMN)64 Atlanta(COLUMN)89(COLUMN)70 Atlantic City(COLUMN)77(COLUMN)74 Austin(COLUMN)99(COLUMN)72 Baltimore(COLUMN)87(COLUMN)73 Billings(COLUMN)76(COLUMN)52 Birmingham(COLUMN)92(COLUMN)69 Bismarck(COLUMN)80(COLUMN)47 Boise(COLUMN)82(COLUMN)50 Boston(COLUMN)73(COLUMN)66 Brownsville(COLUMN)100(COLUMN)78 Buffalo(COLUMN)77(COLUMN)64 Burlington, Vt.(COLUMN)69(COLUMN)67 Casper(COLUMN)75(COLUMN)49 Charleston, S.C.(COLUMN)91(COLUMN)79 Charleston, W.V.(COLUMN)89(COLUMN)68 Charlotte(COLUMN)93(COLUMN)71 Cheyenne(COLUMN)71(COLUMN)51 Chicago(COLUMN)82(COLUMN)65 Cincinnati(COLUMN)87(COLUMN)66 Cleveland(COLUMN)88(COLUMN)64 Columbia, S.C.(COLUMN)95(COLUMN)71 Columbus(COLUMN)88(COLUMN)66 Dal.-Ft. Worth(COLUMN)95(COLUMN)71 Dayton(COLUMN)87(COLUMN)66 Denver(COLUMN)77(COLUMN)57 Des Moines(COLUMN)84(COLUMN)59 Detroit(COLUMN)87(COLUMN)64 Duluth(COLUMN)72(COLUMN)52 El Paso(COLUMN)96(COLUMN)70 Evansville(COLUMN)94(COLUMN)71 Fairbanks(COLUMN)94(COLUMN)71 Fargo(COLUMN)76(COLUMN)48 Flagstaff(COLUMN)82(COLUMN)40 Great Falls(COLUMN)79(COLUMN)48 Hartford(COLUMN)71(COLUMN)69 Helena(COLUMN)73(COLUMN)51 Honolulu(COLUMN)89(COLUMN)72 Houston(COLUMN)82(COLUMN)73 Indianapolis(COLUMN)87(COLUMN)71 Jackson(COLUMN)91(COLUMN)76 Jacksonville(COLUMN)93(COLUMN)72 Juneau(COLUMN)71(COLUMN)53 Kansas City(COLUMN)84(COLUMN)61 Las Vegas(COLUMN)105(COLUMN)73 Little Rock(COLUMN)93(COLUMN)69 Los Angeles(COLUMN)87(COLUMN)67 Louisville(COLUMN)93(COLUMN)70 Memphis(COLUMN)91(COLUMN)73 Miami Beach(COLUMN)87(COLUMN)81 Midland(COLUMN)94(COLUMN)64 Milwaukee(COLUMN)78(COLUMN)62 Mpls.-St. Paul(COLUMN)77(COLUMN)53 Nashville(COLUMN)92(COLUMN)71 New Orleans(COLUMN)89(COLUMN)77 New York(COLUMN)78(COLUMN)73 Norfolk(COLUMN)93(COLUMN)75 North Platte(COLUMN)78(COLUMN)46 Oklahoma City(COLUMN)92(COLUMN)71 Omaha(COLUMN)77(COLUMN)57 Orlando(COLUMN)93(COLUMN)73 Philadelphia(COLUMN)86(COLUMN)77 Phoenix(COLUMN)107(COLUMN)72 Pittsburgh(COLUMN)85(COLUMN)66 Portland, Me.(COLUMN)56(COLUMN)60 Portland, Ore.(COLUMN)85(COLUMN)63 Providence(COLUMN)74(COLUMN)69 Raleigh(COLUMN)93(COLUMN)73 Reno(COLUMN)90(COLUMN)48 Richmond(COLUMN)93(COLUMN)73 St. Louis(COLUMN)84(COLUMN)68 St. Prbg.-Tampa(COLUMN)91(COLUMN)75 Salt Lake City(COLUMN)85(COLUMN)51 San Antonio(COLUMN)97(COLUMN)73 San Diego(COLUMN)75(COLUMN)68 San Francisco(COLUMN)74(COLUMN)56 San Juan(COLUMN)91(COLUMN)78 St. Ste. Marie(COLUMN)69(COLUMN)56 Seattle(COLUMN)79(COLUMN)60 Shreveport(COLUMN)82(COLUMN)71 Sioux Falls(COLUMN)74(COLUMN)52 Spokane(COLUMN)78(COLUMN)54 Syracuse(COLUMN)80(COLUMN)65 Topeka(COLUMN)85(COLUMN)60 Tucson(COLUMN)99(COLUMN)74 Tulsa(COLUMN)93(COLUMN)71 Washington(COLUMN)90(COLUMN)76 Wichita(COLUMN)89(COLUMN)67(END TABLE) Temperatures Abroad Yesterday(TABLE) City(COLUMN)Weather(COLUMN)Time(COLUMN)Temp. Aberdeen(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)55 Amsterdam(COLUMN)rain(COLUMN)1 p.m.(COLUMN)57 Ankara(COLUMN)clear(COLUMN)3 p.m.(COLUMN)84 Athens(COLUMN)clear(COLUMN)2 p.m.(COLUMN)86 Auckland(COLUMN)clear(COLUMN) mid.(COLUMN)45 Berlin(COLUMN)rain(COLUMN)1 p.m.(COLUMN)55 Birmingham(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)61 Bonn(COLUMN)rain(COLUMN)1 p.m.(COLUMN)63 Brussels(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)59 Casablanca(COLUMN)clear(COLUMN) noon(COLUMN)75 Copenhagen(COLUMN)coludy(COLUMN)1 p.m.(COLUMN)61 Dublin(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)61 Geneva(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)66 Hong Kong(COLUMN)cloudy(COLUMN)8 p.m.(COLUMN)81 Jerusalem(COLUMN)clear(COLUMN)2 p.m.(COLUMN)82 Lisbon(COLUMN)cloudy(COLUMN) noon(COLUMN)75 London(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)63 Madrid(COLUMN)clear(COLUMN)1 p.m.(COLUMN)86 Malta(COLUMN)clear(COLUMN)1 p.m.(COLUMN)82 Manila(COLUMN)cloudy(COLUMN)8 p.m.(COLUMN)79 Moscow(COLUMN)rain(COLUMN)3 p.m.(COLUMN)54 New Delhi(COLUMN)clear(COLUMN)5 p.m.(COLUMN)93 Nice(COLUMN)clear(COLUMN)1 p.m.(COLUMN)77 Oslo(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)61 Paris(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)68 Peking(COLUMN)cloudy(COLUMN)8 p.m.(COLUMN)68 Rome(COLUMN)clear(COLUMN)1 p.m.(COLUMN)81 Saigon(COLUMN)cloudy(COLUMN)8 p.m.(COLUMN)82 Sofia(COLUMN)pt. cldy.(COLUMN)2 p.m.(COLUMN)68 Stockholm(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)59 Sydney(COLUMN)pt. cldy.(COLUMN)10 p.m.(COLUMN)59 Tokyo(COLUMN)clear(COLUMN)9 p.m.(COLUMN)82 Tunis(COLUMN)clear(COLUMN)1 p.m.(COLUMN)88 Vienna(COLUMN)clear(COLUMN)1 p.m.(COLUMN)68 Warsaw(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)59(END TABLE) Temperatures (Western Hemisphere)(TABLE) City(COLUMN)Weather(COLUMN)High(COLUMN)Low Barbados(COLUMN)pt. cldy.(COLUMN)88(COLUMN)75 Bermuda(COLUMN)pt. cldy.(COLUMN)85(COLUMN)77 Calgary(COLUMN)clear(COLUMN)70(COLUMN)41 Culiacan(COLUMN)pt. cldy.(COLUMN)96(COLUMN)77 Edmonton(COLUMN)clear(COLUMN)70(COLUMN)41 Havana(COLUMN)pt. cldy.(COLUMN)88(COLUMN)75 Kingston(COLUMN)pt. cldy.(COLUMN)88(COLUMN)75 Montego Bay(COLUMN)pt. cldy.(COLUMN)91(COLUMN)77 Mexico City(COLUMN)pt. cldy.(COLUMN)81(COLUMN)57 Monterrey(COLUMN)pt cldy.(COLUMN)100(COLUMN)75 Montreal(COLUMN)cloudy(COLUMN)72(COLUMN)64 Nassau(COLUMN)pt. cldy.(COLUMN)91(COLUMN)74 Ottawa(COLUMN)cloudy(COLUMN)72(COLUMN)61 Regina(COLUMN)clear(COLUMN)77(COLUMN)45 St. Kitts(COLUMN)pt. cldy.(COLUMN)89(COLUMN)77 St. Thomas(COLUMN)pt. cldy.(COLUMN)89(COLUMN)74 Toronto(COLUMN)cloudy(COLUMN)84(COLUMN)59 Vancouver(COLUMN)clear(COLUMN)72(COLUMN)55 Veracruz(COLUMN)pt. cldy.(COLUMN)93(COLUMN)77 Winnipeg(COLUMN)clear(COLUMN)75(COLUMN)52(END TABLE)