Washington: Today and Tuesday - Variable cloudiness, warm and humid with a chance of an occasional thunderstorm. Highs will be 85 to 90, lows near 70. The chance of rain is 50 percent through tonight. Winds will be from the south at 12 mph.

Maryland and Virginia: Today and Tuesday - Variable cloudiness, warm and humid, with a chance of an occasional thunderstorm, high in the 60 to near 90, low in the 60s to low 70s.

Extended Area Forecast for Wednesday through Friday - Variable cloudiness and humid through the period with a chance of isolated thunderstorms. Highs will be in the 80s low in the 60s. Normal Washington temperatures are a high of 84 and a low of 65.

Lower Potomac and Chesapeake Bay - Variable cloudiness with a chance of occasional thunderstorms. Visbility will be less than 1 mile in showers and morning fog, 1 to 3 miles at other times. Winds will be southerly at 12 to 18 knots shifting the southwest at 12 knots by nightfall. Waves will average 1 to 3 feet.

Atlantic Ocean Beaches from New Jersey to North Carolina: Today and Tuesday - Variable cloudiness with a chance of thunderstorms each afternoon. Highs will range from the upper 70s to upper 80s. Water temperatures will range from the mid 70s to near 80.

West Virginia: Today and Tuesday - Occasional showers and thundershowers, warm and humid with patchy fog both days. Highs will be in the 80s to near 90 lows in the 60s to near 70.

The National Weather Forecast for Today - Showers and thunderstorms will extend from the Great Lakes through the middle of lower Mississippi Valley, and eastward to the Atlantic Coast from the Carolinas to the southern half of New England. Thundershowers will also be scattered across the Plains. Skies will be mostly sunny from the Pacific Coast states across the Rockies, over northern New England and Florida. Temperatures will be mild from the northern Plateau across the northern and central Rockies into the northern half of the Plains and through the Great Lakes into New England. The extreme southwestern corner of the country will continue hot, while warm temperature will prevail across most of the remainder of the nation.

Almanac Data for today: The sun rises 6:33 a.m., sets 7:45 p.m.; moon rises 2:04 a.m., sets 4:32 p.m. Tides: High, 4:50 a.m. and 5:23 p.m.; low, 11:46 a.m. and 12 midnight. High and low tides at the following locations may be obtained by subtracting the hours indicated from the hours above: Annapolis (3 1/2), Bloody Point Lighthouse (4 1/2), Deale, Md. (4 1/2), Colonial Beach (5 1/2), Norfolk, (1), Virginia Beach (3/4), Solomons Island (6 1/4), Point Lookout (7).

The Council of Governments' Air Quality Index for yesterday showed the high reading in the Washington area during the 1 p.m. period was 40 for the pollutant, photochemical oxidants. Index values between 25 and 49 indicate fair 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 3.1 feet today.

Washington data for yesterday: Highest temperature since midnight yesterday, 87 degrees at 2:40 p.m. Lowest temperature since midnight, 76 degrees at 2:30 a.m. Excess of temperature since Aug. 1, 109 degrees. Deficiency of temperature since Jan. 1, 32 degrees. Record high temperature for today, 99 degrees in 1948. Record low temperature for today, 50 degrees in 1874. Relative humidity: Maximum, 82 percent at 3 a.m.; minimum, 61 percent at 2 p.m. 24-hour precipitation, trace. Deficiency of precipitation since Aug. 1, .68 inches. Excess of precipitation since Jan. 1, 2:01 inches. Highest observed wind since 8 a.m., 14 miles per hour from the south at 2:54 p.m. Peak gust since 8 a.m., 21 miles per hour from the south at 5:10 p.m. Local Temps., Humidity(TABLE) Time(COLUMN)T.(COLUMN)H. 12 midnight(COLUMN)77(COLUMN)79 1 a.m.(COLUMN)77(COLUMN)79 2 a.m.(COLUMN)77(COLUMN)79 3 a.m.(COLUMN)76(COLUMN)82 4 a.m.(COLUMN)76(COLUMN)82 5 a.m.(COLUMN)76(COLUMN)82 6 a.m.(COLUMN)76(COLUMN)82 7 a.m.(COLUMN)76(COLUMN)82 8 a.m.(COLUMN)77(COLUMN)79 9 a.m.(COLUMN)77(COLUMN)79 10 a.m.(COLUMN)77(COLUMN)79 11 a.m.(COLUMN)80(COLUMN)72 12 noon(COLUMN)82(COLUMN)67 1 p.m.(COLUMN)84(COLUMN)63 2 p.m.(COLUMN)86(COLUMN)61 3 p.m.(COLUMN)87(COLUMN)61 4 p.m.(COLUMN)86(COLUMN)61 5 p.m.(COLUMN)84(COLUMN)65 6 p.m.(COLUMN)83(COLUMN)67 7 p.m.(COLUMN)81(COLUMN)72(END TABLE) Temperatures ending 8 a.m. (EDT) yesterday:(TABLE) City(COLUMN)H.(COLUMN)L. Albany(COLUMN)75(COLUMN)50 Albuquerque(COLUMN)89(COLUMN)60 Amarillo(COLUMN)89(COLUMN)65 Anchorage(COLUMN)71(COLUMN)48 Asheville(COLUMN)88(COLUMN)62 Atlanta(COLUMN)88(COLUMN)72 Atlantic City(COLUMN)74(COLUMN)70 Austin(COLUMN)97(COLUMN)76 Baltimore(COLUMN)83(COLUMN)69 Billings(COLUMN)78(COLUMN)59 Birmingham(COLUMN)93(COLUMN)71 Bismarck(COLUMN)80(COLUMN)64 Boise(COLUMN)74(COLUMN)45 Boston(COLUMN)68(COLUMN)59 Brownsville(COLUMN)95(COLUMN)73 Buffalo(COLUMN)76(COLUMN)56 Burlington, Vt.(COLUMN)70(COLUMN)46 Casper(COLUMN)82(COLUMN)50 Charleston, S.C.(COLUMN)95(COLUMN)77 Charleston, W.V.(COLUMN)83(COLUMN)70 Charlotte(COLUMN)87(COLUMN)69 Cheyenne(COLUMN)84(COLUMN)53 Chicago(COLUMN)82(COLUMN)72 Cincinnati(COLUMN)83(COLUMN)67 Cleveland(COLUMN)83(COLUMN)64 Columbia, S.C.(COLUMN)94(COLUMN)68 Columbus(COLUMN)83(COLUMN)70 Dal.-Ft. Worth(COLUMN)100(COLUMN)79 Dayton(COLUMN)86(COLUMN)64 Denver(COLUMN)90(COLUMN)54 Des Moines(COLUMN)89(COLUMN)69 Detroit(COLUMN)84(COLUMN)68 Duluth(COLUMN)64(COLUMN)56 El Paso(COLUMN)90(COLUMN)72 Evansville(COLUMN)93(COLUMN)70 Fairbanks(COLUMN)70(COLUMN)46 Fargo(COLUMN)84(COLUMN)65 Flagstaff(COLUMN)79(COLUMN)36 Great Falls(COLUMN)74(COLUMN)55 Hartford(COLUMN)76(COLUMN)53 Helena(COLUMN)74(COLUMN)54 Honolulu(COLUMN)88(COLUMN)73 Houston(COLUMN)92(COLUMN)77 Indianapolis(COLUMN)86(COLUMN)70 Jackson(COLUMN)95(COLUMN)69 Jacksonville(COLUMN)93(COLUMN)69 Juneau(COLUMN)71(COLUMN)50 Kansas City(COLUMN)96(COLUMN)71 Las Vegas(COLUMN)100(COLUMN)65 Little Rock(COLUMN)100(COLUMN)78 Los Angeles(COLUMN)81(COLUMN)65 Louisville(COLUMN)90(COLUMN)72 Memphis(COLUMN)95(COLUMN)78 Midland(COLUMN)89(COLUMN)66 Milwaukee(COLUMN)72(COLUMN)65 Mpls. -St. Paul(COLUMN)79(COLUMN)68 Nashville(COLUMN)89(COLUMN)72 New Orleans(COLUMN)91(COLUMN)77 New York(COLUMN)78(COLUMN)66 Norfolk(COLUMN)84(COLUMN)69 North Platte(COLUMN)90(COLUMN)54 Oklahoma City(COLUMN)101(COLUMN)75 Omaha(COLUMN)88(COLUMN)69 Orlando(COLUMN)93(COLUMN)71 Philadelphia(COLUMN)85(COLUMN)69 Phoenix(COLUMN)105(COLUMN)74 Pittsburgh(COLUMN)81(COLUMN)59 Portland, Me.(COLUMN)72(COLUMN)47 Portland, Ore.(COLUMN)75(COLUMN)55 Providence(COLUMN)72(COLUMN)58 Raleigh(COLUMN)87(COLUMN)69 Rapid City(COLUMN)86(COLUMN)59 Reno(COLUMN)83(COLUMN)43 Richmond(COLUMN)87(COLUMN)71 St. Louis(COLUMN)92(COLUMN)73 St. Prbg.-Tampa(COLUMN)91(COLUMN)75 Salt Lake City(COLUMN)88(COLUMN)56 San Antonio(COLUMN)94(COLUMN)73 San Diego(COLUMN)77(COLUMN)69 San Francisco(COLUMN)64(COLUMN)56 San Juan(COLUMN)90(COLUMN)70 St. Ste. Marie(COLUMN)73(COLUMN)59 Seattle(COLUMN)74(COLUMN)56 Shreveport(COLUMN)100(COLUMN)68 Sioux Falls(COLUMN)77(COLUMN)65 Spokane(COLUMN)73(COLUMN)45 Syracuse(COLUMN)76(COLUMN)60 Topeka(COLUMN)97(COLUMN)71 Tucson(COLUMN)101(COLUMN)72 Tulsa(COLUMN)104(COLUMN)78 Washington(COLUMN)88(COLUMN)-6 Wichita(COLUMN)100(COLUMN)74(END TABLE) Temperatures Abroad Yesterday(TABLE) City(COLUMN)Weather(COLUMN)Time(COLUMN)Temp. Aberdeen(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)52 Amsterdam(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)55 Ankara(COLUMN)clear(COLUMN)3 p.m.(COLUMN)61 Athens(COLUMN)clear(COLUMN)2 p.m.(COLUMN)72 Auckland(COLUMN)cloudy(COLUMN)noon(COLUMN)59 Berlin(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)54 Birmingham(COLUMN)clear(COLUMN)1 p.m.(COLUMN)54 Bonn(COLUMN)clear(COLUMN)1 p.m.(COLUMN)43 Brussels(COLUMN)clear(COLUMN)1 p.m.(COLUMN)48 Casablanca(COLUMN)cloudy(COLUMN)midnight(COLUMN)72 Copenhagen(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)54 Dublin(COLUMN)clear(COLUMN)1 p.m.(COLUMN)54 Geneva(COLUMN)clear(COLUMN)1 p.m.(COLUMN)55 Hong Kong(COLUMN)rain(COLUMN)midnight(COLUMN)79 Lisbon(COLUMN)clear(COLUMN)midnight(COLUMN)66 London(COLUMN)haze(COLUMN)1 p.m.(COLUMN)52 Madrid(COLUMN)clear(COLUMN)1 p.m.(COLUMN)70 Malta(COLUMN)clear(COLUMN)1 p.m.(COLUMN)70 Manila(COLUMN)pt. cldy.(COLUMN)8 p.m.(COLUMN)82 Moscow(COLUMN)cloudy(COLUMN)3 p.m.(COLUMN)59 New Delhi(COLUMN)cloudy(COLUMN)5 p.m.(COLUMN)81 Nice(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)72 Paris(COLUMN)clear(COLUMN)1 p.m.(COLUMN)54 Peking(COLUMN)rain(COLUMN)8 p.m.(COLUMN)75 Saigon(COLUMN)pt. cldy.(COLUMN)8 p.m.(COLUMN)77 Sofia(COLUMN)clear(COLUMN)2 p.m.(COLUMN)52 Stockholm(COLUMN)rain(COLUMN)1 p.m.(COLUMN)52 Sydney(COLUMN)clear(COLUMN)10 p.m.(COLUMN)52 Tokyo(COLUMN)pt. cldy.(COLUMN)9 p.m.(COLUMN)81 Tunis(COLUMN)clear(COLUMN)1 p.m.(COLUMN)70 Vienna(COLUMN)clear(COLUMN)54 Warsaw(COLUMN)clear(COLUMN)1 p.m.(COLUMN)50(END TABLE) Temperatures (Western Hemisphere)(TABLE) City(COLUMN)Weather(COLUMN)High(COLUMN)Low Acapulco(COLUMN)pt. cldy.(COLUMN)90(COLUMN)78 Barbados(COLUMN)pt. cldy.(COLUMN)86(COLUMN)77 Bermuda(COLUMN)pt. cldy.(COLUMN)86(COLUMN)78 Bogota(COLUMN)cloudy(COLUMN)68(COLUMN)49 Calgary(COLUMN)clear(COLUMN)70(COLUMN)39 Culiacan(COLUMN)fair(COLUMN)89(COLUMN)77 Edmonton(COLUMN)clear(COLUMN)70(COLUMN)43 Havana(COLUMN)pt. cldy.(COLUMN)90(COLUMN)77 Kingston(COLUMN)pt. cldy.(COLUMN)89(COLUMN)78 Montego Bay(COLUMN)pt. cldy.(COLUMN)87(COLUMN)73 Mexico City(COLUMN)haze(COLUMN)78(COLUMN)54 Monterrey(COLUMN)pt. cldy.(COLUMN)96(COLUMN)75 Montreal(COLUMN)pt. cldy.(COLUMN)73(COLUMN)43 Nassau(COLUMN)pt. cldy.(COLUMN)88(COLUMN)74 Ottawa(COLUMN)cloudy(COLUMN)73(COLUMN)50 Regina(COLUMN)clear(COLUMN)73(COLUMN)45 St. Kitts(COLUMN)pt. cldy.(COLUMN)89(COLUMN)77 St. Thomas(COLUMN)pt. cldy.(COLUMN)91(COLUMN)80 Toronto(COLUMN)cloudy(COLUMN)75(COLUMN)55 Vancouver(COLUMN)pt. cldy.(COLUMN)70(COLUMN)50 Veracruz(COLUMN)pt. cldy.(COLUMN)88(COLUMN)74 Winnipeg(COLUMN)rain(COLUMN)84(COLUMN)64(END TABLE)