WASHINGTON: Today - Partly cloudy and humid with a chance of afternoon or evening thundershowers, high in low 90s, low in mid 70s. Chance of rain is 40 percent through tonight. Winds will be southerly at 10 mph. Monday - Partly cloudy, high in low 90s.

Maryland and Virginia: Today - Mostly cloudy with a chance of afternoon or evening thundershowers, high in mid 90s, low in mid 60s. Monday - Cloudy, high in mid 90s.

Lower Potomac and Chesapeake Bay: Today - Fair with a chance at thunderstorms this afternoon, visibility more than 5 miles except in rain. Winds will be southerly at 18 knots. Waves in unprotected waters will will be two feet.

Atlantic Ocean Beaches from New Jersey to North Carolina: Today and Monday will be partly cloudy with a chance of thundershowers in northern portions. Highs will be in mid to upper 80s. It will be mostly sunny in the southern portions with a chance of thundershowers, high near 90. Water temperatures will be around 70 in north and near 80 in south.

Extended Area Outlook for Tuesday through Thursday: Variable cloudiness with a chance of thunderstorms each day. Highs will average from the upper 70s to the mid 80s and lows from the mid 60s to the low 70s. Normal Washington temperatures for the period will be a high of 88 and low of 69.

The National Yesterday: The heaviest and most numerous thunderstorms were over the south west Alabama coast and the Florida peninsula.There were rather frequent thundershowers also over the central Appalachians that reached into western and northern New York. Scattered and mostly light thundershowers were located near the common border of Illinois and Wisconsin, over Iowa and eastern Nebraska and southwestern Alabama. Isolated thundershowers still well over small parts of Utah, Wyoming and southwest Texas. Temperatures were in the news again in the Midwest as cool air moved behind a front reaching from Michigan through Illinois, and Kansas into northeastern New Mexico. It was warm and muggy over the south with 80s and 90s prevailing. The southwest deserts registered 90s and also just over the one hundred degree mark. Sunny skies were continuing from west Texas and Oklahoma across most of the southern Rockies, New Mexico and Arizona through California, Nevada and the Pacific northwest.

The National Weather Forecast for today - Scattered thundershowers will be spread from the southern Plains across Texas, the lower Mississippi Valley through the south Atlantic Coast states and be more numerous over Florida the upper Ohio Valley, the north and central Appalachians and New England. Isolated thundershowers will dot the Rockies, the Black Hills and the northern mountains of Arizona. Sunshine will dominate elsewhere in the nation. Mild weather in the 70s will continue over the northern Plains and the northern Great Lakes region and spread through the central Plains, the mid Mississippi and the Ohio Valleys into western New England. Hot weather will continue over the northern half of California, the Pacific Northwest and western half of the intermountain region. The rest of the country will have warm weather.

Almanac Data for today: The sun rises 6:07 a.m., sets 7:21 p.m., moon rises 2:35 a.m., sets 5:02 p.m. Tides: high 5:30 a.m. and 5:59 p.m., low 12:18 p.m. High and low tides at the following locations may be obtained by subtracting the hours indicated from the hours above: Annapolis (3 1/2), 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 12 to 1 p.m. period was 44 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 deteriorate.

The National Weather Service forecasts the Potomac River Stage at Little Falls should remain 3.2 feet today.

Washington data for yesterday: Highest temperature since midnight yesterday, 89 degrees at 4:48 p.m. Lowest temperature since midnight, 66 degrees at 5:15 a.m. Excess of temperature since July 1, 4 degrees. Deficiency of temperature since Jan. 1, 146 degrees. Record high temperature for today, 99 degrees in 1953. Record low temperature for today, 56 degrees in 1914. Relative humidity: maximum, 84 percent at 6 a.m.; minimum, 51 percent at 1 p.m. Deficiency of precipitation since July 1, .69 inch. Excess of precipitation since Jan. 1, 1.84 inches. Highest observed wind since 8 a.m., 17 miles per hour from the southwest at 4:53 p.m. Peak gust since 8 a.m., 25 miles per hour from the southwest at 4:11 p.m. Local Temps., Humidity(TABLE) Time(COLUMN)T.(COLUMN)H. 12 midn.(COLUMN)75(COLUMN)58 1 a.m.(COLUMN)72(COLUMN)66 2 a.m.(COLUMN)71(COLUMN)68 3 a.m.(COLUMN)69(COLUMN)78 4 a.m.(COLUMN)67(COLUMN)78 5 a.m.(COLUMN)67(COLUMN)78 6 a.m.(COLUMN)66(COLUMN)84 7 a.m.(COLUMN)68(COLUMN)78 8 a.m.(COLUMN)71(COLUMN)71 9 a.m.(COLUMN)75(COLUMN)68 10 a.m.(COLUMN)77(COLUMN)58 11 a.m.(COLUMN)80(COLUMN)54 12 noon(COLUMN)82(COLUMN)53 1 p.m.(COLUMN)84(COLUMN)51 2 p.m.(COLUMN)83(COLUMN)57 3 p.m.(COLUMN)27(COLUMN)52 4 p.m.(COLUMN)88(COLUMN)52 5 p.m.(COLUMN)89(COLUMN)50 6 p.m.(COLUMN)89(COLUMN)50 7 p.m.(COLUMN)86(COLUMN)57 8 p.m.(COLUMN)85(COLUMN)61 9 p.m.(COLUMN)84(COLUMN)65 10 p.m.(COLUMN)83(COLUMN)70(END TABLE) Temperatures ending 8 a.m. (EDT) yesterday:(TABLE) City(COLUMN)H.(COLUMN)L. Albany(COLUMN)76(COLUMN)52 Albuquerque(COLUMN)98(COLUMN)71 Amarillo(COLUMN)95(COLUMN)67 Anchorage(COLUMN)65(COLUMN)54 Asheville(COLUMN)87(COLUMN)57 Atlanta(COLUMN)90(COLUMN)68 Atlantic City(COLUMN)79(COLUMN)62 Austin(COLUMN)93(COLUMN)75 Baltimore(COLUMN)88(COLUMN)59 Billings(COLUMN)74(COLUMN)56 Birmingham(COLUMN)86(COLUMN)70 Bismarck(COLUMN)84(COLUMN)58 Boise(COLUMN)96(COLUMN)63 Boston(COLUMN)83(COLUMN)62 Brownsville(COLUMN)96(COLUMN)77 Buffalo(COLUMN)74(COLUMN)58 Burlington(COLUMN)73(COLUMN)50 Casper(COLUMN)90(COLUMN)55 Charleston, S.C.(COLUMN)90(COLUMN)76 Charleston, W. Va.(COLUMN)83(COLUMN)63 Charlotte(COLUMN)89(COLUMN)71 Cheyenne(COLUMN)90(COLUMN)57 Chicago(COLUMN)79(COLUMN)70 Cincinnati(COLUMN)81(COLUMN)62 Cleveland(COLUMN)74(COLUMN)60 Columbia, S.C.(COLUMN)91(COLUMN)70 Columbus(COLUMN)81(COLUMN)63 Dal.-Ft. Worth(COLUMN)100(COLUMN)72 Dayton(COLUMN)79(COLUMN)63 Denver(COLUMN)95(COLUMN)63 Des Moines(COLUMN)90(COLUMN)70 Detroit(COLUMN)78(COLUMN)61 Duluth(COLUMN)70(COLUMN)62 El Paso(COLUMN)95(COLUMN)72 Fairbanks(COLUMN)79(COLUMN)53 Fargo(COLUMN)90(COLUMN)61 Flagstaff(COLUMN)86(COLUMN)52 Great Falls(COLUMN)84(COLUMN)57 Hartford(COLUMN)83(COLUMN)59 Helena(COLUMN)83(COLUMN)54 Honolulu(COLUMN)87(COLUMN)73 Houston(COLUMN)88(COLUMN)76 Indianapolis(COLUMN)84(COLUMN)67 Jackson, Miss.(COLUMN)87(COLUMN)75 Jacksonville(COLUMN)89(COLUMN)72 Juneau(COLUMN)66(COLUMN)40 Kansas City(COLUMN)95(COLUMN)72 Las Vegas(COLUMN)102(COLUMN)72 Little Rock(COLUMN)93(COLUMN)76 Los Angeles(COLUMN)87(COLUMN)66 Louisville(COLUMN)86(COLUMN)65 Memphis(COLUMN)92(COLUMN)77 Miami Beach(COLUMN)87(COLUMN)80 Midland-Odessa(COLUMN)92(COLUMN)68 Milwaukee(COLUMN)74(COLUMN)67 Mpls.-St. Paul(COLUMN)84(COLUMN)68 Nashville(COLUMN)89(COLUMN)69 New Orleans(COLUMN)90(COLUMN)77 New York(COLUMN)82(COLUMN)64 Norfolk(COLUMN)85(COLUMN)73 North Platte(COLUMN)99(COLUMN)65 Oklahoma City(COLUMN)100(COLUMN)74 Omaha(COLUMN)92(COLUMN)70 Orlando(COLUMN)87(COLUMN)72 Philadelphia(COLUMN)88(COLUMN)63 Phoenix(COLUMN)111(COLUMN)85 Pittsburgh(COLUMN)79(COLUMN)59 Portland, Me.(COLUMN)82(COLUMN)51 Portland, Ore.(COLUMN)80(COLUMN)57 Providence(COLUMN)81(COLUMN)61 Raleigh(COLUMN)89(COLUMN)68 Rapid City(COLUMN)88(COLUMN)61 Reno(COLUMN)93(COLUMN)49 Richmond(COLUMN)90(COLUMN)66 St. Louis(COLUMN)86(COLUMN)72 St. Prbg.-Tampa(COLUMN)91(COLUMN)77 Salt Lake City(COLUMN)96(COLUMN)67 San Antonio(COLUMN)89(COLUMN)73 San Diego(COLUMN)78(COLUMN)70 San Francisco(COLUMN)59(COLUMN)53 San Juan(COLUMN)87(COLUMN)73 St. Ste. Marie(COLUMN)74(COLUMN)56 Seattle(COLUMN)78(COLUMN)57 Shreveport(COLUMN)96(COLUMN)73 Sioux Falls(COLUMN)88(COLUMN)65 Spokane(COLUMN)88(COLUMN)58 Syracuse(COLUMN)73(COLUMN)53 Topeka(COLUMN)93(COLUMN)62 Tucson(COLUMN)103(COLUMN)75 Tulsa(COLUMN)101(COLUMN)79 Washington(COLUMN)92(COLUMN)66 Wichita(COLUMN)100(COLUMN)70(END TABLE) Temperatures Abroad Yesterday(TABLE) City(COLUMN)Weather(COLUMN)Time(COLUMN)Temp. Aberdeen(COLUMN)clear(COLUMN) 1 p.m.(COLUMN)66 Amsterdam(COLUMN)clear(COLUMN) 1 p.m.(COLUMN)79 Ankara(COLUMN)pt. cldy.(COLUMN) 3 p.m.(COLUMN)73 Athens(COLUMN)clear(COLUMN) 2 p.m.(COLUMN)82 Auckland(COLUMN)clear(COLUMN)12 a.m.(COLUMN)48 Berlin(COLUMN)clear(COLUMN) 1 p.m.(COLUMN)88 Birmingham(COLUMN)pt. cldy.(COLUMN) 1 p.m.(COLUMN)72 Bonn(COLUMN)clear(COLUMN) 1 p.m.(COLUMN)86 Brussels(COLUMN)clear(COLUMN) 1 p.m.(COLUMN)81 Cairo(COLUMN)clear(COLUMN) 2 p.m.(COLUMN)88 Casablanca(COLUMN)clear(COLUMN)12 p.m.(COLUMN)75 Copenhagen(COLUMN)clear(COLUMN) 1 p.m.(COLUMN)77 Dublin(COLUMN)cloudy(COLUMN) 1 p.m.(COLUMN)68 Geneva(COLUMN)clear(COLUMN) 1 p.m.(COLUMN)81 Hong Kong(COLUMN)rain(COLUMN) 8 p.m.(COLUMN)77 Jerusalem(COLUMN)clear(COLUMN) 2 p.m.(COLUMN)79 Lisbon(COLUMN)pt. cldy(COLUMN)12 p.m.(COLUMN)75 London(COLUMN)cloudy(COLUMN) 1 p.m.(COLUMN)73 Madrid(COLUMN)clear(COLUMN) 1 p.m.(COLUMN)81 Malta(COLUMN)clear(COLUMN) 1 p.m.(COLUMN)84 Manila(COLUMN)cloudy(COLUMN) 8 p.m.(COLUMN)84 Moscow(COLUMN)cloudy(COLUMN) 3 p.m.(COLUMN)68 New Delhi(COLUMN)pt. cldy(COLUMN) 5 p.m.(COLUMN)91 Nice(COLUMN)clear(COLUMN) 1 p.m.(COLUMN)82 Oslo(COLUMN)clear(COLUMN) 1 p.m.(COLUMN)77 Paris(COLUMN)cloudy(COLUMN) 1 p.m.(COLUMN)79 Peking(COLUMN)cloudy(COLUMN) 8 p.m.(COLUMN)79 Rome(COLUMN)clear(COLUMN) 1 p.m.(COLUMN)84 Saigon(COLUMN)cloudy(COLUMN) 8 p.m.(COLUMN)81 Sofia(COLUMN)clear(COLUMN) 2 p.m.(COLUMN)72 Stockholm(COLUMN)clear(COLUMN) 1 p.m.(COLUMN)75 Sydney(COLUMN)clear(COLUMN)10 p.m.(COLUMN)48 Tokyo(COLUMN)clear(COLUMN) 9 p.m.(COLUMN)82 Tunis(COLUMN)clear(COLUMN) 1 p.m.(COLUMN)86 Vienna(COLUMN)clear(COLUMN) 1 p.m.(COLUMN)84 Warsaw(COLUMN)(COLUMN)(COLUMN)(END TABLE) Temperatures (Western Hemisphere)(TABLE) City(COLUMN)Weather(COLUMN)High(COLUMN)Low Acapulco(COLUMN)cloudy(COLUMN)90(COLUMN)73 Barbados(COLUMN)pt. cldy(COLUMN)86(COLUMN)78 Calgary(COLUMN)pt. cldy(COLUMN)73(COLUMN)54 Edmonton(COLUMN)clear(COLUMN)73(COLUMN)54 Havana(COLUMN)cloudy(COLUMN)90(COLUMN)77 Kingston(COLUMN)fair(COLUMN)91(COLUMN)78 Montego Bay(COLUMN)cloudy(COLUMN)91(COLUMN)77 Mexico City(COLUMN)haze(COLUMN)73(COLUMN)99 Monterrey(COLUMN)pt. cldy(COLUMN)90(COLUMN)75 Montreal(COLUMN)cloudy(COLUMN)73(COLUMN)57 Nassau(COLUMN)pt. cldy(COLUMN)90(COLUMN)71 Ottawa(COLUMN)cloudy(COLUMN)75(COLUMN)54 Regina(COLUMN)pt. cldy(COLUMN)68(COLUMN)48 St. Kitts(COLUMN)cloudy(COLUMN)88(COLUMN)77 Toronto(COLUMN)rain(COLUMN)75(COLUMN)57 Vancouver(COLUMN)clear(COLUMN)77(COLUMN)55 Veracruz(COLUMN)pt. cldy(COLUMN)88(COLUMN)75 Winnipeg(COLUMN)cloudy(COLUMN)77(COLUMN)54(END TABLE)