Washington: Today - Partly cloudy, chance of thundershowers, high in low 90s, low near 70. The chance of rain is 10 per cent today and 20 per cent tonight. Friday - Partly cloudy, high in the low 90s.

Maryland and Virginia: Today - Partly cloudy, highs from the 80s to the low 90s, lows from the 60s to the low 70s. Friday - Partly cloudy, highs from the 80s to the low 90s.

Lower Potomac and Chesapeake Bay: Today - Partly cloudy, chance of thundershowers. Wind will be from the southwest at from 10 to 15 knots. Visibility will be more than 5 miles. Waves in unprotected waters will be less than 2 feet.

Atlantic Ocean Beaches: From Cape May to Cape Hatteras: Today and Friday - Partly cloudy, chance of afternoon or evening thundershowers, highs from the low 80s to near 90. Water temperatures will range from the low 70s to near 80.

West Virginia: Today - Rain, highs from the upper 70s to the mid '80s, lows from the near 60s to near 70. Friday - Rain, highs from the upper 70s to the mid 80s.

Extended Area Forecast for Saturday through Monday: Warm and humid through the period, chance of thundershowers on each day.Highs will be from the mid 80s to the 90s, lows from the 60s, in the mountains, to the 70s, elsewhere. Normal Washington temperatures for the period are a high of 87 and a low of 68.

The National Weather Forecast for today - Showers and thunderstorms will extend from the Atlantic Coast across the Gulf Coast, through the south half of the Mississippi Valley and Plains, into south portions of New Mexico and Arizona. It will be seasonably mild from the Rockies and the upper three-quarters of the Plains into the upper Mississippi Valley. Temperatures will be hot over the Pacific Northwest. Elsewhere, the nation will continue to be warm.

The Council of Government's Air Quality Index for yesterday showed the high reading in the Washington Area during the 2 p.m. to 3 p.m. period was 115 for the pollutant photochemical oxidants.When the index exceeds 100, the air is considered hazardous, 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 will be near 2.6 feet today.

Washington data at 8 p.m. (EDT) yesterday: Highest temperature since 8 a.m. yesterday, 93 degrees at 3:20 p.m. Lowest temperature since midnight, 77 degrees at 1:01 a.m. Excess of temperature since August 1, 70 degrees. Excess of temperature since Jan. 1, 317 degrees. Record high temperature for today, 98 degrees in 1943. Record low temperature for today, 55 degrees in 1919, Relative humidity: Maximum, 85 per cent at 1 a.m. Minimum, 52 per ent at 5 p.m. 24 hour precipitation, .09 inches. Excess of precipitation since August 1, .32 inches. Deficiency of precipitation since Jan 7, 6.16 inches. Highest observed wind since 8 a.m. 11 miles per hour from the southeast at 5 p.m. Local Temp., Humidity(TABLE) Time(COLUMN)T.(COLUMN)H. 12 mid.(COLUMN)81(COLUMN)72 1 a.m.(COLUMN)77(COLUMN)85 2 a.m.(COLUMN)77(COLUMN)85 3 a.m.(COLUMN)77(COLUMN)85 4 a.m.(COLUMN)77(COLUMN)85 5 a.m.(COLUMN)75(COLUMN)76 6 a.m.(COLUMN)77(COLUMN)85 7 a.m.(COLUMN)77(COLUMN)85 8 a.m.(COLUMN)78(COLUMN)79 9 a.m.(COLUMN)80(COLUMN)74 10 a.m.(COLUMN)83(COLUMN)70 11 a.m.(COLUMN)83(COLUMN)70 12 noon(COLUMN)86(COLUMN)63 1 p.m.(COLUMN)89(COLUMN)58 2 p.m.(COLUMN)92(COLUMN)53 3 p.m.(COLUMN)92(COLUMN)53 4 p.m.(COLUMN)92(COLUMN)53 5 p.m.(COLUMN)91(COLUMN)52 6 p.m.(COLUMN)93(COLUMN)52 7 p.m.(COLUMN)93(COLUMN)52(END TABLE) Temperatures ending 8 a.m. (EDT) Yesterday(TABLE) City(COLUMN)H.(COLUMN)L. Albany(COLUMN)82(COLUMN)58 Albuquerque(COLUMN)95(COLUMN)67 Amarillo(COLUMN)90(COLUMN)68 Anchorage(COLUMN)63(COLUMN)57 Asheville(COLUMN)85(COLUMN)66 Atlanta(COLUMN)91(COLUMN)68 Atlantic City(COLUMN)88(COLUMN)77 Austin(COLUMN)98(COLUMN)75 Baltimore(COLUMN)91(COLUMN)75 Billings(COLUMN)84(COLUMN)51 Birmingham(COLUMN)92(COLUMN)75 Bismarck(COLUMN)85(COLUMN)46 Boise(COLUMN)92(COLUMN)55 Boston(COLUMN)88(COLUMN)64 Brownsville(COLUMN)96(COLUMN)78 Buffalo(COLUMN)80(COLUMN)65 Burlington(COLUMN)73(COLUMN)53 Casper(COLUMN)84(COLUMN)52 Charleston, S.C.(COLUMN)94(COLUMN)78 Charleston, W. Va.(COLUMN)84(COLUMN)69 Charlotte(COLUMN)95(COLUMN)73 Cheyenne(COLUMN)81(COLUMN)53 Chicago(COLUMN)77(COLUMN)73 Cincinnati(COLUMN)85(COLUMN)71 Cleveland(COLUMN)81(COLUMN)71 Columbia, S.C.(COLUMN)96(COLUMN)68 Columbus(COLUMN)84(COLUMN)70 Dal-Ft. Worth(COLUMN)100(COLUMN)77 Dayton(COLUMN)84(COLUMN)71 Denver(COLUMN)85(COLUMN)66 Des Moines(COLUMN)83(COLUMN)68 Detroit(COLUMN)80(COLUMN)68 Duluth(COLUMN)71(COLUMN)54 El Paso(COLUMN)99(COLUMN)66 Fairbanks(COLUMN)75(COLUMN)60 Fargo(COLUMN)82(COLUMN)46 Flagstaff(COLUMN)80(COLUMN)52 Great Falls(COLUMN)65(COLUMN)45 Hartford(COLUMN)88(COLUMN)61 Helena(COLUMN)71(COLUMN)48 Honolulu(COLUMN)89(COLUMN)77 Houston(COLUMN)94(COLUMN)78 Indianapolis(COLUMN)84(COLUMN)72 Jackson, Miss.(COLUMN)94(COLUMN)71 Jacksonville(COLUMN)94(COLUMN)72 Juneau(COLUMN)60(COLUMN)54 Kansas City(COLUMN)90(COLUMN)73 Las Vegas(COLUMN)107(COLUMN)80 Little Rock(COLUMN)98(COLUMN)77 Los Angeles(COLUMN)82(COLUMN)63 Louisville(COLUMN)89(COLUMN)73 Memphis(COLUMN)96(COLUMN)80 Miami Beach(COLUMN)85(COLUMN)82 Midland-Odessa(COLUMN)100(COLUMN)75 Milwaukee(COLUMN)74(COLUMN)64 Mpls.-St. Paul(COLUMN)70(COLUMN)63 Nashville(COLUMN)95(COLUMN)73 New Orleans(COLUMN)92(COLUMN)73 New York(COLUMN)90(COLUMN)71 Norfolk(COLUMN)93(COLUMN)77 North Platte(COLUMN)86(COLUMN)57 Oklahoma City(COLUMN)94(COLUMN)72 Omaha(COLUMN)81(COLUMN)66 Orlando(COLUMN)87(COLUMN)73 Philadelphia(COLUMN)90(COLUMN)72 Phoenix(COLUMN)105(COLUMN)83 Pittsburgh(COLUMN)80(COLUMN)66 Portland, Maine(COLUMN)81(COLUMN)49 Portland, Ore.(COLUMN)99(COLUMN)63 Providence(COLUMN)88(COLUMN)62 Raleigh(COLUMN)95(COLUMN)74 Rapid City(COLUMN)87(COLUMN)48 Reno(COLUMN)92(COLUMN)51 Richmond(COLUMN)93(COLUMN)74 St. Louis(COLUMN)86(COLUMN)70 St. Prbg.-Tampa(COLUMN)91(COLUMN)75 Salt Lake City(COLUMN)90(COLUMN)57 San Antonio(COLUMN)94(COLUMN)76 San Diego(COLUMN)76(COLUMN)68 San Francisco(COLUMN)60(COLUMN)55 San Juan(COLUMN)87(COLUMN)76 St. Ste. Marie(COLUMN)72(COLUMN)55 Seattle(COLUMN)91(COLUMN)63 Shreveport(COLUMN)94(COLUMN)70 Sioux Falls(COLUMN)86(COLUMN)79 Spokane(COLUMN)88(COLUMN)62 Syracuse(COLUMN)78(COLUMN)58 Topeka(COLUMN)97(COLUMN)73 Tucson(COLUMN)95(COLUMN)72 Tulsa(COLUMN)101(COLUMN)77 Wahington(COLUMN)90(COLUMN)77 Wichita(COLUMN)100(COLUMN)76(END TABLE) Temperatures Abroad Yesterday(TABLE) City(COLUMN)Weather(COLUMN)Time(COLUMN)Temp. Aberdeen(COLUMN)clear(COLUMN)1 p.m.(COLUMN)64 Amsterdam(COLUMN)rain(COLUMN)1 p.m.(COLUMN)59 Ankara(COLUMN)clear(COLUMN)3 p.m.(COLUMN)82 Athens(COLUMN)clear(COLUMN)2 p.m.(COLUMN)91 Auckland(COLUMN)cloudy(COLUMN)midnight(COLUMN)52 Berlin(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)66 Birmingham(COLUMN)clear(COLUMN)1 p.m.(COLUMN)72 Brussels(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)64 Cairo(COLUMN)clear(COLUMN)2 p.m.(COLUMN)90 Casablanca(COLUMN)clear(COLUMN)noon(COLUMN)75 Copenhagen(COLUMN)clear(COLUMN)1 p.m.(COLUMN)70 Dublin(COLUMN)pt. cloudy(COLUMN)1 p.m.(COLUMN)66 Geneva(COLUMN)clear(COLUMN)1 p.m.(COLUMN)68 Hong Kong(COLUMN)pt. cldy(COLUMN)8 p.m.(COLUMN)84 Lisbon(COLUMN)clear(COLUMN)noon(COLUMN)72 London(COLUMN)clear(COLUMN)1 p.m.(COLUMN)72 Madrid(COLUMN)clear(COLUMN)1 p.m.(COLUMN)86 Malta(COLUMN)clear(COLUMN)1 p.m.(COLUMN)88 Manila(COLUMN)clear(COLUMN)8 p.m.(COLUMN)82 Moscow(COLUMN)rain(COLUMN)3 p.m.(COLUMN)66 New Delhi(COLUMN)cloudy(COLUMN)5 p.m.(COLUMN)84 Nice(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)75 Oslo(COLUMN)pt. cldy.(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)rain(COLUMN)8 p.m.(COLUMN)77 Sofia(COLUMN)rain(COLUMN)2 p.m.(COLUMN)72 Stockholm(COLUMN)rain(COLUMN)1 p.m.(COLUMN)61 Sydney(COLUMN)clear(COLUMN)10 p.m.(COLUMN)61 Tel Aviv(COLUMN)pt. cldy.(COLUMN)2 p.m.(COLUMN)88 Tokyo(COLUMN)rain(COLUMN)9 p.m.(COLUMN)77 Tunis(COLUMN)rain(COLUMN)1 p.m.(COLUMN)88 Vienna(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)72 Warsaw(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)75(END TABLE) Temperatures (Western Hemisphere)(TABLE) City(COLUMN)Weather(COLUMN)High(COLUMN)Low Acapulco(COLUMN)cloudy(COLUMN)89(COLUMN)77 Barbados(COLUMN)fair(COLUMN)82(COLUMN)76 Bermuda(COLUMN)sunny(COLUMN)85(COLUMN)81 Bogota(COLUMN)pt. cldy.(COLUMN)64(COLUMN)42 Calgary(COLUMN)clear(COLUMN)61(COLUMN)37 Culiacan(COLUMN)pt. cldy.(COLUMN)93(COLUMN)75 Edmonton(COLUMN)clear(COLUMN)61(COLUMN)36 Havana(COLUMN)pt. cldy.(COLUMN)88(COLUMN)73 Kingston(COLUMN)pt. cldy.(COLUMN)87(COLUMN)77 Montego Bay(COLUMN)pt. cldy.(COLUMN)87(COLUMN)73 Mexico City(COLUMN)pt. cldy.(COLUMN)76(COLUMN)57 Monterrey(COLUMN)pt. cldy.(COLUMN)96(COLUMN)75 Montreal(COLUMN)cloudy(COLUMN)73(COLUMN)55 Nassau(COLUMN)pt. cldy.(COLUMN)88(COLUMN)77 Ottawa(COLUMN)cloudy(COLUMN)75(COLUMN)55 Regina(COLUMN)cloudy(COLUMN)64(COLUMN)55 St. Kitts(COLUMN)pt. cldy.(COLUMN)90(COLUMN)75 St. Thomas(COLUMN)sunny(COLUMN)89(COLUMN)80 Toronto(COLUMN)cloudy(COLUMN)73(COLUMN)61 Vancouver(COLUMN)clear(COLUMN)79(COLUMN)63 Veracruz(COLUMN)cloudy(COLUMN)87(COLUMN)68 Winnipeg(COLUMN)clear(COLUMN)84(COLUMN)46(END TABLE)