Washington: Today - Warm and humid with a chance of afternoon or evening thundershowers, high near 90, low near 65. The chance of rain is 40 percent through tonight. Winds will be from the southwest at 10 to 15 mph. Thursday - Chance of morning showers followed by clearing skies, high in the 80s.

Maryland and Virginia: Today - Warm and humid with a chance of afternoon or evening thundershowers, high near 90, low in the 60s. Thursday - Chance of morning showers followed by clearing, high in the 80s.

Extended Area Forecast for Friday through Sunday - Fair and pleasant through Sunday with near normal temperatures. Normal Washington temperatures are a high of 86 and a low of 66.

Lower Potomac and Chesapeake Bay - Partly cloudy with a chance of afternoon or evening thundershowers. Visibility will be 3 to 5 miles diminishing to less than 1 mile in showers. Winds will be from the south at 10 to 18 knots. Waves will average 1 to 2 feet.

Atlantic Ocean Beaches from New Jersey to Maryland: Today - Partly cloudy, warm and humid with a chance of afternoon and evening thundershowers, high in the low 80s. Thursday - Chance of morning showers, high near 80. Water temperatures will be in the low to mid 60s.

Atlantic Ocean Beaches from Virginia to North Carolina - Today - Partly cloudy, warm and humid with a chance of afternoon or evening thundershowers, high in the 80s. Thursday - Chance of morning showers, high in the low 80s. Water temperatures will range from the mid 60s to low 70s.

West Virginia: Today - Variable cloudiness with a few thunderstorms likely, highs from the mid 70s to mid 80s, lows from the upper 50s to mid 60s. Thursday - Partly cloudy, high near 80.

The National Weather Forecast for today - showers and thunderstorms will be scattered from the lower Great Lakes area across the upper Ohio Valley, the middle Atlantic Coast states and most of the Southeast. A few thundershowers will dot the Great Basin region and the northern Rockies. Skies will be sunny through most of the interior of the nation and the Southwest. Mild temperatures will be seen from the Great Lakes region across the upper Mississippi Valley and the northern Plains. It will be generally warm elsewhere, except for continued hot readings in the Desert Southwest.

The Council of Governments' Air Quality Index for yesterday showed the high reading in the Washington area during the 3 p.m. period was 104 for the pollutant, photochemical oxidants. Index values between 100 and 149 indicate very unhealthy air quality. When the index exceeds 100 the 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 improve.

The National Weather Service forecasts the Potomac River Stage at Little Falls should remain near 3.3 feet today.

Almanac Data for today: The sun rises 5:43 a.m., sets 8:37 p.m., moon rises 9:21 p.m., sets 6:43 a.m. Tides: High 9:04 a.m. and 9:36 p.m., low 3:19 a.m. and 4:03 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 1/4), Norfolk (1), Virginia Beach (3/4), Solomons Island (6 1/4), Point Lookout (7).

Pollen Count: 6 English Plaintain (a reading of more than 7 is considered to be undesirable). Local Temps., Humidity(TABLE) Time(COLUMN)T.(COLUMN)H. 12 m'night(COLUMN)75(COLUMN)88 1 a.m.(COLUMN)75(COLUMN)88 2 a.m.(COLUMN)74(COLUMN)82 3 a.m.(COLUMN)73(COLUMN)74 4 a.m.(COLUMN)72(COLUMN)74 5 a.m.(COLUMN)71(COLUMN)74 6 a.m.(COLUMN)69(COLUMN)79 7 a.m.(COLUMN)71(COLUMN)76 8 a.m.(COLUMN)75(COLUMN)62 9 a.m.(COLUMN)77(COLUMN)60 10 a.m.(COLUMN)79(COLUMN)58 11 a.m.(COLUMN)81(COLUMN)55 12 noon(COLUMN)82(COLUMN)53 1 p.m.(COLUMN)84(COLUMN)48 2 p.m.(COLUMN)86(COLUMN)45 3 p.m.(COLUMN)87(COLUMN)45 4 p.m.(COLUMN)87(COLUMN)48 5 p.m.(COLUMN)87(COLUMN)52 6 p.m.(COLUMN)86(COLUMN)55 7 p.m.(COLUMN)85(COLUMN)57(END TABLE) Temperatures ending 8 a.m. (EDT) yesterday:(TABLE) City(COLUMN)H.(COLUMN)L. Albany(COLUMN)85(COLUMN)56 Albuquerque(COLUMN)97(COLUMN)63 Amarillo(COLUMN)92(COLUMN)67 Anchorage(COLUMN)59(COLUMN)43 Asheville(COLUMN)83(COLUMN)65 Atlanta(COLUMN)86(COLUMN)66 Atlantic City(COLUMN)91(COLUMN)62 Austin(COLUMN)93(COLUMN)71 Baltimore(COLUMN)94(COLUMN)63 Billings(COLUMN)63(COLUMN)42 Birmingham(COLUMN)85(COLUMN)66 Bismarck(COLUMN)73(COLUMN)47 Boise(COLUMN)76(COLUMN)49 Boston(COLUMN)80(COLUMN)56 Brownsville(COLUMN)91(COLUMN)74 Buffalo(COLUMN)74(COLUMN)55 Burlington, Vt.(COLUMN)77(COLUMN)61 Casper(COLUMN)75(COLUMN)40 Charleston, S.C.(COLUMN)83(COLUMN)72 Charleston, W.V.(COLUMN)80(COLUMN)65 Charlotte(COLUMN)87(COLUMN)66 Cheyenne(COLUMN)79(COLUMN)41 Chicago(COLUMN)72(COLUMN)64 Cincinnati(COLUMN)82(COLUMN)64 Cleveland(COLUMN)82(COLUMN)59 Columbia, S.C.(COLUMN)86(COLUMN)61 Columbus(COLUMN)81(COLUMN)58 Dal.-Ft. Worth(COLUMN)96(COLUMN)75 Dayton(COLUMN)81(COLUMN)60 Denver(COLUMN)86(COLUMN)50 Des Moines(COLUMN)86(COLUMN)65 Detroit(COLUMN)84(COLUMN)52 Duluth(COLUMN)82(COLUMN)53 El Paso(COLUMN)104(COLUMN)72 Fairbanks(COLUMN)56(COLUMN)46 Fargo(COLUMN)83(COLUMN)48 Flagstaff(COLUMN)85(COLUMN)41 Great Falls(COLUMN)58(COLUMN)44 Hartford(COLUMN)91(COLUMN)59 Helena(COLUMN)61(COLUMN)38 Honolulu(COLUMN)86(COLUMN)73 Houston(COLUMN)88(COLUMN)76 Indianapolis(COLUMN)84(COLUMN)65 Jackson(COLUMN)88(COLUMN)70 Jacksonville(COLUMN)84(COLUMN)68 Juneau(COLUMN)50(COLUMN)47 Kansas City(COLUMN)87(COLUMN)66 Las Vegas(COLUMN)103(COLUMN)70 Little Rock(COLUMN)88(COLUMN)71 Los Angeles(COLUMN)85(COLUMN)64 Louisville(COLUMN)81(COLUMN)68 Memphis(COLUMN)88(COLUMN)73 Miami Beach(COLUMN)85(COLUMN)76 Midland(COLUMN)93(COLUMN)70 milwaukee(COLUMN)73(COLUMN)58 Mpls.-St. Paul(COLUMN)85(COLUMN)56 Nashville(COLUMN)82(COLUMN)67 New Orleans(COLUMN)89(COLUMN)68 New York(COLUMN)91(COLUMN)65 Norfolk(COLUMN)90(COLUMN)69 North Platte(COLUMN)86(COLUMN)52 Oklahoma City(COLUMN)90(COLUMN)75 Omaha(COLUMN)89(COLUMN)59 Orlando(COLUMN)89(COLUMN)72 Philadelphia(COLUMN)93(COLUMN)66 Phoenix(COLUMN)112(COLUMN)75 Pittsburgh(COLUMN)80(COLUMN)61 Portland, Me.(COLUMN)67(COLUMN)52 Portland, Ore.(COLUMN)76(COLUMN)56 Providence(COLUMN)88(COLUMN)65 Raleigh(COLUMN)90(COLUMN)66 Rapid City(COLUMN)77(COLUMN)45 Reno(COLUMN)84(COLUMN)42 Richmond(COLUMN)93(COLUMN)67 St. Louis(COLUMN)84(COLUMN)69 St. Prbg.-Tampa(COLUMN)88(COLUMN)76 Salt Lake City(COLUMN)77(COLUMN)53 San Antonio(COLUMN)93(COLUMN)75 San Diego(COLUMN)83(COLUMN)67 San Francisco(COLUMN)62(COLUMN)53 San Juan(COLUMN)88(COLUMN)77 St. Ste. Marie(COLUMN)79(COLUMN)46 Seattle(COLUMN)75(COLUMN)55 Shreveport(COLUMN)95(COLUMN)70 Sioux Falls(COLUMN)83(COLUMN)47 Spokane(COLUMN)72(COLUMN)48 Syracuse(COLUMN)71(COLUMN)54 Topeka(COLUMN)88(COLUMN)64 Tucson(COLUMN)107(COLUMN)73 Tulsa(COLUMN)99(COLUMN)74 Washington(COLUMN)96(COLUMN)69 Wichita(COLUMN)93(COLUMN)64(END TABLE) Temperatures Abroad Yesterday(TABLE) City(COLUMN)Weather(COLUMN)Time(COLUMN)Temp. Aberdeen(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)68 Amsterdam(COLUMN)clear(COLUMN)1 p.m.(COLUMN)72 Ankara(COLUMN)pt. cldy.(COLUMN)3 p.m.(COLUMN)72 Athens(COLUMN)clear(COLUMN)2 p.m.(COLUMN)91 Auckland(COLUMN)cloudy(COLUMN)midnight(COLUMN)52 Berlin(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)75 Birmingham(COLUMN)clear(COLUMN)1 p.m.(COLUMN)66 Bonn(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)70 Brussels(COLUMN)clear(COLUMN)1 p.m.(COLUMN)70 Casablanca(COLUMN)pt. cldy.(COLUMN)noon(COLUMN)66 Copenhagen(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)66 Dublin(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)59 Geneva(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)66 Hong Kong(COLUMN)pt. cldy.(COLUMN)8 p.m.(COLUMN)84 Jerusalem(COLUMN)clear(COLUMN)2 p.m.(COLUMN)86 Lisbon(COLUMN)clear(COLUMN)2 p.m.(COLUMN)72 London(COLUMN)clear(COLUMN)1 p.m.(COLUMN)72 Madrid(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)61 Malta(COLUMN)clear(COLUMN)1 p.m.(COLUMN)84 Manila(COLUMN)cloudy(COLUMN)8 p.m.(COLUMN)79 Moscow(COLUMN)cloudy(COLUMN)3 p.m.(COLUMN)50 New Delhi(COLUMN)Pt. cldy.(COLUMN)5 p.m.(COLUMN)90 Nice(COLUMN)clear(COLUMN)1 p.m.(COLUMN)73 Oslo(COLUMN)clear(COLUMN)1 p.m.(COLUMN)72 Paris(COLUMN)clear(COLUMN)1 p.m.(COLUMN)70 Peking(COLUMN)clear(COLUMN)8 p.m.(COLUMN)79 Rome(COLUMN)clear(COLUMN)1 p.m.(COLUMN)79 Saigon(COLUMN)cloudy(COLUMN)8 p.m.(COLUMN)82 Sofia(COLUMN)clear(COLUMN)2 p.m.(COLUMN)70 Stockholm(COLUMN)clear(COLUMN)1 p.m.(COLUMN)68 Sydney(COLUMN)rain(COLUMN)10 p.m.(COLUMN)55 Tokyo(COLUMN)pt. cldy.(COLUMN)9 p.m.(COLUMN)79 Tunis(COLUMN)clear(COLUMN)1 p.m.(COLUMN)81 Vienna(COLUMN)clear(COLUMN)1 p.m.(COLUMN)73 Warsaw(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)73(END TABLE) Temperatures (Western Hemisphere)(TABLE) City(COLUMN)Weather(COLUMN)High(COLUMN)Low Acapulco(COLUMN)pt. cldy.(COLUMN)90(COLUMN)76 Barbados(COLUMN)cloudy(COLUMN)88(COLUMN)77 Bermuda(COLUMN)fair(COLUMN)78(COLUMN)71 Bogota(COLUMN)cloudy(COLUMN)67(COLUMN)51 Calgary(COLUMN)clear(COLUMN)64(COLUMN)45 Edmonton(COLUMN)cloudy(COLUMN)66(COLUMN)52 Havana(COLUMN)cloudy(COLUMN)86(COLUMN)73 Kingston(COLUMN)fair(COLUMN)90(COLUMN)80 Montego Bay(COLUMN)clear(COLUMN)91(COLUMN)77 Mexico City(COLUMN)haze(COLUMN)74(COLUMN)59 Monterrey(COLUMN)fair(COLUMN)95(COLUMN)70 Montreal(COLUMN)rain(COLUMN)72(COLUMN)61 Nassau(COLUMN)pt. cldy.(COLUMN)83(COLUMN)83 Ottawa(COLUMN)pt. cldy.(COLUMN)70(COLUMN)59 Regina(COLUMN)clear(COLUMN)61(COLUMN)41 St. Kitts(COLUMN)fair(COLUMN)89(COLUMN)77 St. Thomas(COLUMN)fair(COLUMN)88(COLUMN)78 Toronto(COLUMN)clear(COLUMN)79(COLUMN)45 Vancouver(COLUMN)clear(COLUMN)70(COLUMN)52 Veracruz(COLUMN)pt. cldy.(COLUMN)88(COLUMN)74 Winnipeg(COLUMN)cloudy(COLUMN)72(COLUMN)48(END TABLE)