Washington: Today - Warm and humid, high near 90, low near 70. The chance of rain is 20 per cent through tonight. Friday - Continued warm and humid, high near 90.

Maryland and Virginia: Today - Warm and humid, highs in the upper 80s to low 90s, low near 70. Friday - Continued warm and humid, high near 90.

Extended Area Forecast for Saturday through Monday - Continued warm and humid with a chance of late afternoon or early evening thundershowers each day. Highs will be near 90, lows near 70. Normak Washington temperatures for the period are a high of 83 and a low of 64.

Lower Potomac and Chesapeake Bay: Today - Fair with good visibility except in early morning haze. Winds will be southerly at 8 knots or less.

Atlantic Ocean Beaches from Cape May to Cape Hatteras: Today and Friday - Mostly sunny, warm and humid, high in the 80s. Water temperature will range from the lower 70s in the north to near 80 in the south.

West Virginia: Today - Warm and humid, highs will range from mid 80s, to the mid 90s, low from the mid 60s, to low 70s. Friday - Continued warm and humid, high near 90.

The National Weather Forecast for Today - Showers and occasional thunderstorms will extend from Florida across the Gulf of Mexico through eastern Texas, into the southern Plains, northern New Mexico, over the central Mississippi Valley and east portions of the central Plains, from western New England across the Great Lakes and Ohio Valley, over the northern Plains and the northern half of the Pacific Coast. It will be mild from the upper Great Lakes through most of the Plains and the northern half of the Pacific Coast. Temperatures will be cool over the upper Missouri Valley and northern half of the Rockies into the eastern protions of the Great Basin. Elsewhere, temperatures over the nation will be warm and occasionaly hot.

ALMANAC DATA FOR 9-1-77. Sun rises 6:37 a.m., sets 7:39 p.m.; moon rises 9:46 p.m. sets 10:26 a.m. Tides: High 11:19 a.m. and 11:45 p.m., low 5:50 a.m. and 6:04 p.m. High and low tides at the following locations can be obtained by subtracting the hours indicated from the tides above. Annapolis (3 1/2); Bloody Point Lighthouse (4 1/2); Deale, Md. (4 1/2); Colonial Beach (6); Norfolk (1 1/2); VIrginia Beach (1); Solomons Island (6 1/2); Point Lookout (7).

The coucil of Governments' Air Quality Index for yesterday showed the high reading in the Washington area during the 4 p.m. period was 110 for the polluttant, photochemical oxidants. Index values between 100 and 249 indicate very unhealthy air quality. When the index exceeds 100 the air is considered very unhealthy and individuals wlith lung, heart and eye ailments are urged to restrict their activity. The air pollution alert has been extended through 4 p.m. today.

The National Weather Service forecasts the Potomac River stage at Little Falls should rise slightly today.

Washington data at 8 p.m. (EDT) yesterday: Highest temperature since 8 a.m. yesterday, 90 degrees at 2:30 p.m. Lowest temperature since midnight, 72 degrees at 5:30 a.m. Excess of temperature since Aug. 1, 59 degrees. Excess of temperature since Jan. 1, 336 degrees. Record high tempeature for today, 99 degrees in 1953. Record low temperature for today, 50 degrees in 1890. Relative humidity: Maximum, 94 per cent at 2 a.m.; Minumum, 64 per cent at 4 p.m. 24 hour precipitation, none. Excess of precipitation since Aug. 1, .07 inches. Deficiency of precipitation since Jan. 1, 6.41 inches. Highest observed wind since 8 a.m. 10 miles per hour from the south at 7 p.m. Local Temp., Humidity(TABLE) Time(COLUMN)T.(COLUMN)H. 12 mid(COLUMN)75(COLUMN)91 1 a.m.(COLUMN)75(COLUMN)91 2 a.m.(COLUMN)74(COLUMN)94 3 a.m.(COLUMN)74(COLUMN)94 4 a.m.(COLUMN)73(COLUMN)97 5 a.m.(COLUMN)74(COLUMN)94 6 a.m.(COLUMN)73(COLUMN)94 7 a.m.(COLUMN)74(COLUMN)94 8 a.m.(COLUMN)75(COLUMN)91 9 a.m.(COLUMN)78(COLUMN)88 10 a.m.(COLUMN)81(COLUMN)82 11 a.m.(COLUMN)84(COLUMN)75 12 noon(COLUMN)86(COLUMN)80 1 p.m.(COLUMN)87(COLUMN)75 2 p.m.(COLUMN)89(COLUMN)68 3 p.m.(COLUMN)88(COLUMN)68 4 p.m.(COLUMN)90(COLUMN)64 5 p.m.(COLUMN)89(COLUMN)68 6 p.m.(COLUMN)86(COLUMN)72 7 p.m.(COLUMN)85(COLUMN)68(END TABLE) Temperatures ending 8 a.m. (EDT) yesterday.(TABLE) City(COLUMN)H.(COLUMN)L. Albany(COLUMN)80(COLUMN)58 Albuquerque(COLUMN)84 60 Amarillo86(COLUMN)68 Anchorage(COLUMN)66(COLUMN)47 Asheville(COLUMN)86(COLUMN)62 Atlanta(COLUMN)88(COLUMN)70 Atlantic City(COLUMN)84(COLUMN)73 Austin(COLUMN)94(COLUMN)74 Baltimore(COLUMN)94(COLUMN)72 Billings(COLUMN)63(COLUMN)43 Birmingham(COLUMN)94(COLUMN)73 Bismarck(COLUMN)76(COLUMN)53 Boise(COLUMN)71(COLUMN)43 Boston(COLUMN)89(COLUMN)69 Brownsville(COLUMN)93(COLUMN)77 Buffalo(COLUMN)78(COLUMN)59 Burlington, Vt.(COLUMN)74(COLUMN)55 Casper(COLUMN)85(COLUMN)34 Charteston, S.C.(COLUMN)89(COLUMN)77 Charleston, W.Va.(COLUMN)83(COLUMN)68 Charlotte(COLUMN)93(COLUMN)72 Cheyenne(COLUMN)81(COLUMN)55 Chicago(COLUMN)82(COLUMN)69 Cincinnati(COLUMN)85(COLUMN)67 Cleveland(COLUMN)78(COLUMN)62 Columbia, S.C.(COLUMN)91(COLUMN)69 Coloumbus(COLUMN)80(COLUMN)65 Dal.-Ft. Worth(COLUMN)94(COLUMN)72 Dayton(COLUMN)82(COLUMN)64 Denver(COLUMN)89(COLUMN)56 Des Moines(COLUMN)85(COLUMN)67 Detroit(COLUMN)84(COLUMN)61 Duluth(COLUMN)66(COLUMN)62 El Paso(COLUMN)90(COLUMN)71 Fairbanks(COLUMN)61(COLUMN)42 Fargo(COLUMN)77(COLUMN)54 Flagstaff(COLUMN)82(COLUMN)47 Great Falls(COLUMN)55(COLUMN)38 Hartford(COLUMN)89(COLUMN)66 Helena(COLUMN)53(COLUMN)37 Honolulu(COLUMN)86(COLUMN)78 Houston(COLUMN)88(COLUMN)73 Indianapolis(COLUMN)85(COLUMN)66 Jackson(COLUMN)92(COLUMN)72 Jacksonville(COLUMN)90(COLUMN)70 Juneau(COLUMN)62(COLUMN)43 Kansas City(COLUMN)86(COLUMN)74 Las Vegas(COLUMN)104(COLUMN)80 Little Rock(COLUMN)90(COLUMN)74 Los Angeles(COLUMN)82(COLUMN)67 Louisville(COLUMN)90(COLUMN)72 Mimphis(COLUMN)96(COLUMN)75 Miami Beach(COLUMN)88(COLUMN)80 Midland(COLUMN)94(COLUMN)69 Milwaukee(COLUMN)73(COLUMN)66 Mpls.-St. Paul(COLUMN)76(COLUMN)65 Nashville(COLUMN)92(COLUMN)71 New Orleans(COLUMN)87(COLUMN)77 New York(COLUMN)87(COLUMN)72 Norfolk(COLUMN)91(COLUMN)71 North Platte(COLUMN)86(COLUMN)55 Oklahoma City(COLUMN)90(COLUMN)71 Omaha(COLUMN)85(COLUMN)63 Orlando(COLUMN)90(COLUMN)74 Philadelphia(COLUMN)92(COLUMN)74 Phoenix(COLUMN)106(COLUMN)83 Pittsburgh(COLUMN)75(COLUMN)63 Portland, Me.(COLUMN)80(COLUMN)62 Portland, Or.(COLUMN)73(COLUMN)51 Providence(COLUMN)86(COLUMN)63 Raleigh(COLUMN)90(COLUMN)68 Rapid City(COLUMN)76(COLUMN)47 Rapid City(COLUMN)76(COLUMN)47 Reno(COLUMN)83(COLUMN)42 Richmond(COLUMN)94(COLUMN)70 St. Louis(COLUMN)84(COLUMN)73 St. Prbg.-Tampa(COLUMN)90(COLUMN)77 Salt Lake City(COLUMN)85(COLUMN)48 San ANtonio(COLUMN)92(COLUMN)73 San Diego(COLUMN)75(COLUMN)70 San Francisco(COLUMN)73(COLUMN)56 San Juan(COLUMN)84(COLUMN)75 St. Ste. Marie(COLUMN)67(COLUMN)55 Seattle(COLUMN)69(COLUMN)51 Shreveport(COLUMN)92(COLUMN)70 Sioux Falls(COLUMN)80(COLUMN)60 Spokane(COLUMN)68(COLUMN)48 Syracuse(COLUMN)77(COLUMN)55 Topelka(COLUMN)90(COLUMN)77 Tucson(COLUMN)100(COLUMN)78 Tulsa(COLUMN)77(COLUMN)73 Washington(COLUMN)92(COLUMN)72 Wichita(COLUMN)88(COLUMN)71(END TABLE) Temperature Abroad Yesterday(TABLE) City(COLUMN)Weather(COLUMN)Time(COLUMN)Temp Aberdeen(COLUMN)Clear(COLUMN)1 p.m.(COLUMN)63 Amsterdam(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)66 Ankara(COLUMN)clear(COLUMN)3 p.m.(COLUMN)72 Athens(COLUMN)clear(COLUMN)2 p.m.(COLUMN)82 Auckland(COLUMN)pt. cldy.(COLUMN)Midnight(COLUMN)54 Berlin(COLUMN)haze(COLUMN)1 p.m.(COLUMN)81 Birmingham(COLUMN)rain(COLUMN)1 p.m.(COLUMN)57 Brussels(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)70 Cairo(COLUMN)clear(COLUMN)2 p.m.(COLUMN)88 Casablance(COLUMN)cloudy(COLUMN)noon(COLUMN)72 Copenhagen(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)72 Dublin(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)64 Geneva(COLUMN)clear(COLUMN)1 p.m.(COLUMN)70 Hong Kong(COLUMN)cloudy(COLUMN)8 p.m.(COLUMN)82 Lisbon(COLUMN)clear(COLUMN)noon(COLUMN)70 Londson(COLUMN)rain(COLUMN)1 p.m.(COLUMN)59 Midrid(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)77 Malta(COLUMN)clear(COLUMN)1 p.m.(COLUMN)82 Manila(COLUMN)rain(COLUMN)8 p.m.(COLUMN)77 Moscow(COLUMN)pt. cldy.(COLUMN)3 p.m.(COLUMN)73 New Dehi(COLUMN)rain(COLUMN)5 p.m.(COLUMN)82 Nice(COLUMN)clear(COLUMN)1 p.m.(COLUMN)73 Osla(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)59 Paris(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)72 Peking(COLUMN)clear(COLUMN)8 p.m.(COLUMN)75 Rome(COLUMN)clear(COLUMN)1 p.m.(COLUMN)77 Saigon(COLUMN)pt. cldy.(COLUMN)8 p.m.(COLUMN)86 Sofia(COLUMN)clear(COLUMN)2 p.m.(COLUMN)72 Stockholm(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)70 Sydney(COLUMN)rain(COLUMN)10 p.m.(COLUMN)55 Tel aviv(COLUMN)clear(COLUMN)2 p.m.(COLUMN)90 Tokyo(COLUMN)cloudy(COLUMN)9 p.m.(COLUMN)79 Tunis(COLUMN)clear(COLUMN)1 p.m.(COLUMN)81 Vienna(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)79 Warsaw(COLUMN)clear(COLUMN)1 p.m.(COLUMN)75(END TABLE) Temperatures (Western Hemisphere)(TABLE) City(COLUMN)Weather(COLUMN)H.(COLUMN)L. Acapulco(COLUMN)clear(COLUMN)91(COLUMN)82 Barbados(COLUMN)pt. cldy(COLUMN)87(COLUMN)82 Bermuda(COLUMN)pt. cldy.(COLUMN)86(COLUMN)79 Bogota(COLUMN)pt. cldy.(COLUMN)68(COLUMN)51 Calgary(COLUMN)cloudy(COLUMN)54(COLUMN)43 Culiacan(COLUMN)cloudy(COLUMN)82(COLUMN)75 Edmonton(COLUMN)rain(COLUMN)55(COLUMN)41 Havana(COLUMN)cloudy(COLUMN)88(COLUMN)78 Kingston(COLUMN)pt. cldy.(COLUMN)90(COLUMN)78 Montego Bay(COLUMN)pt. cldy.(COLUMN)91(COLUMN)75 Mexico City(COLUMN)pt. cldy.(COLUMN)77(COLUMN)75 Montreal(COLUMN)clear(COLUMN)68(COLUMN)54 Nassau(COLUMN)cloudy(COLUMN)87(COLUMN)74 Ottawa(COLUMN)clear(COLUMN)68(COLUMN)50 Regina(COLUMN)cloudy(COLUMN)63(COLUMN)46 St. Kitts(COLUMN)pt. cldy.(COLUMN)89(COLUMN)78 Toronto(COLUMN)cloudy(COLUMN)73(COLUMN)54 Vancouver(COLUMN)pt. cldy.(COLUMN)66(COLUMN)52 Veracruz(COLUMN)pt. cldy.(COLUMN)90(COLUMN)75 Winnipeg(COLUMN)cloudy(COLUMN)70(COLUMN)52(END TABLE)