Washington: Today - Partly cloudy and humid, high 84 to 89, low 68 to 74. Chance of rain is 50 percent through tonight. Winds will be light and variable. Monday - Partly cloudy, high near 90.

Maryland and Virginia: Today - Partly cloudy and humid, high in the 80s, lows in the mid 60s. There will be a chance of afternoon and evening thunderstorms today and Monday. Monday - Partly cloudy, high in the 80s.

Lower Potomac and Chesapeake Bay: Today - Fair, visibility more than five miles. There will be a chance of thunderstorms with briefly strong and gusty winds. Winds will be southerly at 15 knots. Waves in unprotected waters will be 2 feet.

Atlantic Ocean Breaches From New Jersey to North Carolina: Today - Considerable cloudiness and humid with a chance of evening thunderstorms, high in mid 70s to mid 80s. Monday - Partly cloudy and humid, high in mid 70s to mid 80s. Water temperatures will be in the lower 70s in the north, to the mid 70s in the south.

Extended Area Outlook for Tuesday through Thursday: Partly cloudy warm and humid through the period, with a chance of isolated thunderstorms. Highs will average in the 80s to low 90s with lows mostly in the 60s. Normal Washington temperatures for the period will be high of 89 and a low 70.

The National Weather Forecast for today - showers and thunderstorms will range from the the lower Mississippi Valley through the eastern half of the Great Lakes area and eastward to the Atlantic Coast. There is also a chance for showers or thundershowers from the northern plateau across the northern Plains into portions of the upper Great Lakes, and in the the lower Ohio Valley. Much of the remainder of the nation will have sunny to mostly sunny skies. Temperatures will be hot through most of the Plains area, in the southern Rockies and southern California, and through the middle and upper Mississippi Valley. The rest of the country can expect continued warm weather.

Almanac Data for today: The sun rises 5:56 a.m., sets 8:32 p.m.; moon rises 4:56 p.m., sets 2:33 a.m. Tides: high 4:53 a.m. and 5:22 p.m., low 11:07 a.m. and 12:09 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 1/4), Deale, Md. (4 1/4), Colonial Beach (5 1/4), Norfolk (1), Virginia Beach (3/4), Solomons Island (6 1/4), Point Lookout (7).

The Council of Government' Air Quality Index for yesterday showed the high reading in the Washington area during the 12 to 1 p.m. period was 41 for the pollutant, photochemical oxidants. Index values between 25 and 49 indicate 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 near 3.7 feet today. Local Temp., Humidity(TABLE) Time(COLUMN)T.(COLUMN)H. 12 midnight(COLUMN)76(COLUMN)94 1 a.m.(COLUMN)76(COLUMN)94 2 a.m.(COLUMN)75(COLUMN)97 3 a.m.(COLUMN)75(COLUMN)94 4 a.m.(COLUMN)73(COLUMN)97 5 a.m.(COLUMN)74(COLUMN)94 6 a.m.(COLUMN)73(COLUMN)97 8 a.m.(COLUMN)74(COLUMN)94 9 a.m.(COLUMN)76(COLUMN)94 10 a.m.(COLUMN)79(COLUMN)85 11 a.m.(COLUMN)81(COLUMN)77 12 noon(COLUMN)82(COLUMN)77 1 p.m.(COLUMN)83(COLUMN)72 2 p.m.(COLUMN)86(COLUMN)66 3 p.m.(COLUMN)87(COLUMN)61 4 p.m.(COLUMN)88(COLUMN)54 5 p.m.(COLUMN)87(COLUMN)61 6 p.m.(COLUMN)86(COLUMN)65(END TABLE) Temperatures ending 8 a.m. (EDT) yesterday:(TABLE) City(COLUMN)H.(COLUMN)L. Albany(COLUMN)83(COLUMN)66 Albuquerque(COLUMN)99(COLUMN)67 Amarillo(COLUMN)99(COLUMN)71 Anchorage(COLUMN)63(COLUMN)55 Asheville(COLUMN)87(COLUMN)63 Atlanta(COLUMN)87(COLUMN)70 Atlantic City(COLUMN)67(COLUMN)65 Austin(COLUMN)100(COLUMN)78 Baltimore(COLUMN)80(COLUMN)70 Billings(COLUMN)90(COLUMN)59 Birmingham(COLUMN)87(COLUMN)71 Bismarck(COLUMN)90(COLUMN)53 Boise(COLUMN)97(COLUMN)69 Boston(COLUMN)83(COLUMN)66 Brownsville(COLUMN)97(COLUMN)76 Buffalo(COLUMN)83(COLUMN)62 Burlington(COLUMN)82(COLUMN)66 Casper(COLUMN)93(COLUMN)55 Charleston, S.C.(COLUMN)87(COLUMN)77 Charleston, W.V.(COLUMN)81(COLUMN)65 Charlotte(COLUMN)91(COLUMN)68 Cheyenne(COLUMN)91(COLUMN)54 Chicago(COLUMN)81(COLUMN)66 Cincinnati(COLUMN)86(COLUMN)69 Cleveland(COLUMN)80(COLUMN)62 Columbia, S.C.(COLUMN)91(COLUMN)71 Columbus(COLUMN)86(COLUMN)64 Dal.-Ft. Worth(COLUMN)102(COLUMN)77 Dayton(COLUMN)84(COLUMN)66 Denver(COLUMN)97(COLUMN)62 Des Moines(COLUMN)85(COLUMN)68 Detroit(COLUMN)85(COLUMN)64 Duluth(COLUMN)83(COLUMN)52 El Paso(COLUMN)98(COLUMN)77 Fairbanks(COLUMN)75(COLUMN)53 Fargo(COLUMN)83(COLUMN)61 Flagstaff(COLUMN)89(COLUMN)61 Great Falls(COLUMN)89(COLUMN)59 Hartford(COLUMN)80(COLUMN)66 Helena(COLUMN)90(COLUMN)56 Honolulu(COLUMN)85(COLUMN)73 Houston(COLUMN)93(COLUMN)80 Indianapolis(COLUMN)88(COLUMN)73 Jackson, Miss.(COLUMN)92(COLUMN)73 Jacksonville(COLUMN)87(COLUMN)71 Juneau(COLUMN)52(COLUMN)50 Kansas City(COLUMN)95(COLUMN)66 Las Vegas(COLUMN)109(COLUMN)80 Little Rock(COLUMN)91(COLUMN)68 Los Angeles(COLUMN)97(COLUMN)71 Louisville(COLUMN)89(COLUMN)71 Memphis(COLUMN)86(COLUMN)73 Miami Beach(COLUMN)85(COLUMN)70 Midland-Odessa(COLUMN)96(COLUMN)73 Milwaukee(COLUMN)81(COLUMN)66 Mpls.-St. Paul(COLUMN)87(COLUMN)66 Nashville(COLUMN)86(COLUMN)72 New Orleans(COLUMN)92(COLUMN)76 New York(COLUMN)74(COLUMN)67 Norfolk(COLUMN)78(COLUMN)68 North Platte(COLUMN)92(COLUMN)55 Oklahoma City(COLUMN)105(COLUMN)74 Omaha(COLUMN)84(COLUMN)67 Orlando(COLUMN)92(COLUMN)74 Philadelphia(COLUMN)76(COLUMN)69 Phoenix(COLUMN)112(COLUMN)89 Pittsburgh(COLUMN)82(COLUMN)62 Portland, Maine(COLUMN)81(COLUMN)61 Portland, Ore.(COLUMN)90(COLUMN)65 Province(COLUMN)81(COLUMN)65 Raleigh(COLUMN)87(COLUMN)65 Rapid City(COLUMN)91(COLUMN)61 Reno(COLUMN)95(COLUMN)55 Richmond(COLUMN)83(COLUMN)68 St. Louis(COLUMN)91(COLUMN)68 St. Prbg.-Tampa(COLUMN)91(COLUMN)75 Salt Lake City(COLUMN)101(COLUMN)73 San Antonio(COLUMN)98(COLUMN)78 San Diego(COLUMN)86(COLUMN)71 San Francisco(COLUMN)65(COLUMN)52 San Juan(COLUMN)90(COLUMN)65 St. Ste. Marie(COLUMN)79(COLUMN)56 Seattle(COLUMN)85(COLUMN)57 Shreveport(COLUMN)101(COLUMN)75 Sioux Falls(COLUMN)88(COLUMN)57 Spokane(COLUMN)90(COLUMN)60 Topeka(COLUMN)92(COLUMN)62 Tucson(COLUMN)106(COLUMN)82 Tulsa(COLUMN)104(COLUMN)75 Washington(COLUMN)92(COLUMN)73 Wichita(COLUMN)104(COLUMN)69(END TABLE) Temperatures Abroad Yesterday(TABLE) City(COLUMN)Weather(COLUMN)Time(COLUMN)Temp. Aberdeen(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)57 Amsterdam(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)55 Ankara(COLUMN)clear(COLUMN)3 p.m.(COLUMN)86 Athens(COLUMN)clear(COLUMN)2 p.m.(COLUMN)86 Auckland(COLUMN)clear(COLUMN)12 a.m.(COLUMN)44 Berlin(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)57 Birmingham(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)64 Bonn(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)55 Brussels(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)57 Cairo(COLUMN)clear(COLUMN)2 p.m.(COLUMN)97 Casablanca(COLUMN)clear(COLUMN)12 p.m.(COLUMN)77 Copenhagen(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)63 Dublin(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)61 Geneva(COLUMN)clear(COLUMN)1 p.m.(COLUMN)73 Hong Kong(COLUMN)pt. cldy.(COLUMN)8 p.m.(COLUMN)86 Jerusalem(COLUMN)clear(COLUMN)2 p.m.(COLUMN)93 Lisbon(COLUMN)clear(COLUMN)12 p.m.(COLUMN)86 London(COLUMN)clear(COLUMN)1 p.m.(COLUMN)64 Madrid(COLUMN)clear(COLUMN)1 p.m.(COLUMN)97 Malta(COLUMN)clear(COLUMN)1 p.m.(COLUMN)95 Manila(COLUMN)pt. cldy.(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)86 Nice(COLUMN)clear(COLUMN)1 p.m.(COLUMN)77 Oslo(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)59 Paris(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)64 Peking(COLUMN)cloudy(COLUMN)8 p.m.(COLUMN)79 Rome(COLUMN)clear(COLUMN)1 p.m.(COLUMN)81 Saigon(COLUMN)pt. cldy.(COLUMN)8 p.m.(COLUMN)88 Sofia(COLUMN)clear(COLUMN)2 p.m.(COLUMN)81 Stockholm(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)61 Sydney(COLUMN)clear(COLUMN)10 p.m.(COLUMN)43 Tokyo(COLUMN)cloudy(COLUMN)9 p.m.(COLUMN)7.9 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 Acapulco(COLUMN)fair(COLUMN)90(COLUMN)77 Barbados(COLUMN)pt. cldy.(COLUMN)98(COLUMN)79 Bermuda(COLUMN)fair(COLUMN)85(COLUMN)79 Bogota(COLUMN)pt. cldy.(COLUMN)61(COLUMN)42 Calgary(COLUMN)clear(COLUMN)84(COLUMN)48 Culiacan(COLUMN)pt. cldy.(COLUMN)99(COLUMN)75 Edmonton(COLUMN)clear(COLUMN)77(COLUMN)52 Havana(COLUMN)pt. cldy.(COLUMN)88(COLUMN)73 Kingston(COLUMN)pt. cldy.(COLUMN)90(COLUMN)79 Montego Bay(COLUMN)pt. cldy.(COLUMN)86(COLUMN)73 Mexico City(COLUMN)pt. cldy.(COLUMN)75(COLUMN)55 Monterrey(COLUMN)clear(COLUMN)98(COLUMN)75 Montreal(COLUMN)clear(COLUMN)81(COLUMN)59 Nassau(COLUMN)fair(COLUMN)90(COLUMN)77 Ottawa(COLUMN)clear(COLUMN)79(COLUMN)61 Regina(COLUMN)clear(COLUMN)86(COLUMN)63 St. Kitts(COLUMN)pt. cldy.(COLUMN)87(COLUMN)74 St. Thomas(COLUMN)cloudy(COLUMN)89(COLUMN)78 Toronto(COLUMN)clear(COLUMN)86(COLUMN)55 Vancouver(COLUMN)pt. cldy.(COLUMN)81(COLUMN)59 Veracruz(COLUMN)fair(COLUMN)88(COLUMN)75 Winnipeg(COLUMN)cloudy(COLUMN)73(COLUMN)59(END TABLE)