Washington: Today - Partly cloudy, high in 80s, low in mid to upper 60s. Chance of rain is 20 per cent today, 40 per cent tonight. Wednesday - Partly cloudy, high in low 80s.

Maryland and Virginia: Today - Partly cloudy, highs in low to mid 80s, lows in 61s to 71s. Chance of rain tonight. Wednesday - Partly cloudy with chance of rain, highs in mid 70s to mid 80s.

Lower Potomac [WORD ILLEGIBLE] Chesapeake Bay: Today - Fair skies today followed by rain tonight with good visibility today and poor visibility during evening precipitation. Winds should be northwesterly at [WORD ILLEGIBLE] to 15 knots today becoming westerly at 5 knots or less tonight.

Extended Area Outlook: For Thursday through Saturdays - Fair Thursday followed by chance of rain Friday and Saturday. Highs should average in upper [WORD ILLEGIBLE] to mid 80s, lows in 60s. It should be slightly cooler in mountains.Washington's normal temperature range for this time of year is from 85 to 46.

West Virginia: Today - Sunny, high in low to mid 80s, lows in mid 50s to mid 60s. It should be slightly cooler in mountains and in north. Chance of rain in later afternoon and evening. Wednesday - Chance of rain, highs in mid [WORD ILLEGIBLE]

Atlantic Ocean Beaches from Cape May to Cape Hatteras: Today - Partly cloudy, highs in 70s to near 80. Wednesday - Partly cloudy warm chance of rain, highs in 70s to near [WORD ILLEGIBLE]. Water temperatures should range from low to mid 70s in north to low 80s in south.

The National Forecast for Today - Showers and thunderstorms will be scattered through the Gulf and south Atlantic Coast states and extend from the lower Mississippi Valley into Missouri and eastern Kansas. Showers will continue into the [WORD ILLEGIBLE] and westward across Montana into Washington and northern Oregon. There will also be a few showers in the Great Lakes region and northern New England and some thundershowers over the central and southern Rockies. Most other areas will have clear or partly cloudy skies. Temperatures will be a [WORD ILLEGIBLE] cooler in the cooler Mississippi Valley, central Pacific Coast and western Colorade but elsewhere little change is expected. Highs will range from the 60s and 70s across the north and alone the Pacific Coast to the 80s to 90s elsewhere with the southeast desert over 100.

ALMANAC DATA FOR Aug. 23, 1977, Sun rises 6:29 a.m., sets 7:52 a.m., moon rises 3:39 p.m. Tides: High 3:10 a.m. and 3:41 p.m., low 11:25 a.m. and 10:36 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 [WORD ILLEGIBLE] 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); Pollen Court; 17 Ragweed (note: 7 or higher is considered undesirable).

The Council of Governments' Air Quality Index for yesterday showed the high reading in the Washington area during the 2 to 3 p.m. period was 80 for the pollutant, photochemical oxidants. Index values between 50 and 99 indicate unhealthy 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 Ptomac River stage at Little Falls should 2.9 feet through today.

Washington data 8 p.m. (EDT) yesterday: Highest temperature since 8 a.m. yesterday, 86 degrees at 3:20 p.m. Lowest temperature since midnight, 70 degrees at 5:35 a.m. Excess of temperature since Aug. 1, 47 degrees. Excess of temperature since Jan. 1, 324 degrees. Record high temperature for today, 98 degrees in 1936. Record low temperature for today, 52 degrees in 1925. Relative humidity: Maximum, 90 per cent at 6 a.m.; Minimum, 57 per cent at 3 p.m. 24 hour precipitation, none. Deficiency of precipitation since Jan. 1, 6.93 inches. Highest observed wind since 8 a.m. 14 miles per hour from the S.S.W. at 9 a.m. Peak gust since 8 a.m. 27 miles per hour from the SW at 9:01 a.m. Local Temp., Humidity(TABLE) Time(COLUMN)T.(COLUMN)H. 12 m'n(COLUMN)74(COLUMN)79 1 a.m.(COLUMN)74(COLUMN)79 2 a.m.(COLUMN)37(COLUMN)82 3 a.m.(COLUMN)72(COLUMN)84 4 a.m.(COLUMN)71(COLUMN)87 5 a.m.(COLUMN)71(COLUMN)87 6 a.m.(COLUMN)70(COLUMN)90 7 a.m.(COLUMN)71(COLUMN)84 8 a.m.(COLUMN)72(COLUMN)84 9 a.m.(COLUMN)74(COLUMN)79 10 a.m.(COLUMN)76 74 11 a.m.(COLUMN)77(COLUMN)71 12 noon(COLUMN)80(COLUMN)65 1 p.m.(COLUMN)82(COLUMN)63 2 p.m.(COLUMN)82(COLUMN)63 3 p.m.(COLUMN)80(COLUMN)57 4 p.m.(COLUMN)82(COLUMN)61 5 p.m.(COLUMN)80(COLUMN)67 6 p.m.(COLUMN)83(COLUMN)61(END TABLE) Temperatures ending 8 a.m. (EDT) Yesterday(TABLE) City(COLUMN)H.(COLUMN)L. Albany(COLUMN)73(COLUMN)57 Alburquerque(COLUMN)91(COLUMN)67 Amarillo(COLUMN)84(COLUMN)59 Anchorage(COLUMN)82(COLUMN)59 Asheville(COLUMN)71(COLUMN)60 Atlanta(COLUMN)84(COLUMN)66 Atlantic City(COLUMN)76(COLUMN)73 Austin(COLUMN)99(COLUMN)79 Baltimore(COLUMN)80(COLUMN)71 Billings(COLUMN)84(COLUMN)56 Birmingham(COLUMN)87(COLUMN)70 Bismarck(COLUMN)77(COLUMN)47 Boise(COLUMN)91(COLUMN)64 Boston(COLUMN)69(COLUMN)60 Brownsville(COLUMN)94(COLUMN)80 Buffalo(COLUMN)67(COLUMN)58 Burlington Vt.(COLUMN)73(COLUMN)60 Casper(COLUMN)86(COLUMN)57 Char'ton S.C.(COLUMN)83(COLUMN)72 Charlton, W.Va.(COLUMN)82(COLUMN)64 Charlotte, N.C.(COLUMN)87(COLUMN)66 Cheyenne(COLUMN)78(COLUMN)57 Chicago(COLUMN)72(COLUMN)57 Cincinnati(COLUMN)78(COLUMN)61 Cleveland(COLUMN)74(COLUMN)58 Columbia, S.C.(COLUMN)86(COLUMN)63 Columbus, Ohio(COLUMN)75(COLUMN)56 Dal-Ft. Worth(COLUMN)88(COLUMN)76 Dayton(COLUMN)73(COLUMN)54 Denver(COLUMN)85(COLUMN)559 Des Moines(COLUMN)81(COLUMN)58 Detroit(COLUMN)68(COLUMN)54 Duluth(COLUMN)67(COLUMN)48 El Paso(COLUMN)96(COLUMN)66 Fairbanks(COLUMN)87(COLUMN)68 Fairgo(COLUMN)75(COLUMN)55 Flagstaff(COLUMN)82(COLUMN)554 Great Falls(COLUMN)83(COLUMN)54 Hartford(COLUMN)79(COLUMN)60 Helena(COLUMN)87(COLUMN)553 Honolulu(COLUMN)89(COLUMN)78 Houston(COLUMN)94(COLUMN)80 Indianapolis(COLUMN)75(COLUMN)58 Jackson, Miss.(COLUMN)90(COLUMN)74 Jacksonville(COLUMN)86(COLUMN)71 Juneau(COLUMN)78(COLUMN)59 Kansas City(COLUMN)84(COLUMN)60 Las Vegas(COLUMN)105(COLUMN)80 LIttle Rock(COLUMN)88(COLUMN)71 Los Angeles(COLUMN)83(COLUMN)68 Louisville(COLUMN)85(COLUMN)62 Memphis(COLUMN)90(COLUMN)71 Miami Beach(COLUMN)89(COLUMN)78 Midland(COLUMN)99(COLUMN)75 Milwaukee(COLUMN)70(COLUMN)52 Mpls-St. Paul(COLUMN)77(COLUMN)50 Nashville(COLUMN)87(COLUMN)68 New Orleans(COLUMN)90(COLUMN)75 New York(COLUMN)76(COLUMN)65 Norfolk(COLUMN)81(COLUMN)70 North Platte(COLUMN)81(COLUMN)58 Oklahoma City(COLUMN)89(COLUMN)67 Omaha(COLUMN)77(COLUMN)58 Orlando(COLUMN)88(COLUMN)75 Philadelphia(COLUMN)78(COLUMN)66 Phoenix(COLUMN)101(COLUMN)855 Pittsburgh(COLUMN)75(COLUMN)61 Portland, Me.(COLUMN)70(COLUMN)51 Portland, Ore.(COLUMN)67(COLUMN)60 Providence(COLUMN)74(COLUMN)58 Raleigh(COLUMN)84(COLUMN)63 Rapid City(COLUMN)82(COLUMN)58 Reno(COLUMN)94(COLUMN)55 Richmond(COLUMN)83(COLUMN)68 St. Louis(COLUMN)89(COLUMN)63 St. Pbg-Tampa(COLUMN)87(COLUMN)78 Salt Lake City(COLUMN)89(COLUMN)64 San Antonio(COLUMN)96(COLUMN)78 San Diego(COLUMN)74(COLUMN)69 San Francisco(COLUMN)67(COLUMN)55 San Juan, P.R.(COLUMN)87(COLUMN)75 St. Ste. Marie(COLUMN)66(COLUMN)50 Seattle(COLUMN)65(COLUMN)55 Shreveport(COLUMN)78(COLUMN)69 Sioux Falls(COLUMN)77(COLUMN)59 Spokane(COLUMN)90(COLUMN)64 Syracuse(COLUMN)71(COLUMN)60 Topeka(COLUMN)86(COLUMN)59 Tucson(COLUMN)94(COLUMN)77 Tulsa(COLUMN)88(COLUMN)70 Washington(COLUMN)82(COLUMN)80 Wichita(COLUMN)85(COLUMN)70(END TABLE) Temperatures Abroad Yesterday(TABLE) City(COLUMN)Weather(COLUMN)Time(COLUMN)Temp. Aberdeen(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)59 Amsterdam(COLUMN)rain(COLUMN)1 p.m.(COLUMN)59 Ankara(COLUMN)clear(COLUMN)3 p.m.(COLUMN)93 Athens(COLUMN)clear(COLUMN)2 p.m.(COLUMN)90 Auckland(COLUMN)rain(COLUMN)midnight(COLUMN)52 Berlin(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)66 Birmingham(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)61 Brussels(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)63 Cairo(COLUMN)clear(COLUMN)2 p.m.(COLUMN)93 Casablanca(COLUMN)clear(COLUMN)noon(COLUMN)73 Copenhagen(COLUMN)clear(COLUMN)1 p.m.(COLUMN)66 Dublin(COLUMN)clear(COLUMN)1 p.m.(COLUMN)63 Geneva(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)59 Hong Kong(COLUMN)cloudy(COLUMN)8 p.m.(COLUMN)84 Lisbon(COLUMN)pt. cldy.(COLUMN)noon(COLUMN)72 London(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)59 Madrid(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)70 Malta(COLUMN)clear(COLUMN)1 p.m.(COLUMN)82 Manila(COLUMN)cloudy(COLUMN)8 p.m.(COLUMN)84 Moscow(COLUMN)pt. cldy.(COLUMN)3 p.m.(COLUMN)63 New Delhi(COLUMN)pt. cldy.(COLUMN)5 p.m.(COLUMN)95 Nice(COLUMN)clear(COLUMN)1 p.m.(COLUMN)75 Olso(COLUMN)clear(COLUMN)1 p.m.(COLUMN)64 Paris(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)63 Peking(COLUMN)pt. cldy.(COLUMN)8 p.m.(COLUMN)75 Rome(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)75 Saigon(COLUMN)cloudy(COLUMN)8 p.m.(COLUMN)81 Sofia(COLUMN)clear(COLUMN)2 p.m.(COLUMN)91 Stockholm(COLUMN)clear(COLUMN)1 p.m.(COLUMN)64 Sydney(COLUMN)clear(COLUMN)10 p.m.(COLUMN)55 Tel Aviv(COLUMN)clear(COLUMN)2 p.m.(COLUMN)90 Tokyo(COLUMN)cloudy(COLUMN)9 p.m.(COLUMN)70 Tunis(COLUMN)clear(COLUMN)1 p.m.(COLUMN)82 Vienna(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)68 Warsaw(COLUMN)rain(COLUMN)1 p.m.(COLUMN)55(END TABLE) Temperatures (Western Hemisphere)(TABLE) City(COLUMN)Weather(COLUMN)High(COLUMN)Low Acapulo(COLUMN)pt. cldy.(COLUMN)90(COLUMN)78 Barbados(COLUMN)pt. cldy.(COLUMN)86(COLUMN)73 Bermuda(COLUMN)cloudy(COLUMN)85(COLUMN)78 Bogota(COLUMN)pt. cldy.(COLUMN)71(COLUMN)49 Calgary(COLUMN)drizzle(COLUMN)57(COLUMN)45 Culiacan(COLUMN)pt. cldy(COLUMN)94(COLUMN)77 Edmonton(COLUMN)pt. cldy.(COLUMN)61(COLUMN)32 Kingston(COLUMN)fair(COLUMN)90(COLUMN)78 Montego Bay(COLUMN)fair(COLUMN)91(COLUMN)77 Mexico City(COLUMN)pt. cldy.(COLUMN)77(COLUMN)59 Monterrey(COLUMN)fair(COLUMN)101(COLUMN)75 Montreal(COLUMN)rain(COLUMN)72(COLUMN)57 Nassau(COLUMN)fair(COLUMN)92(COLUMN)77 Ottawa(COLUMN)cloudy(COLUMN)70(COLUMN)59 Regina(COLUMN)cloudy(COLUMN)70(COLUMN)41 St. Kitts(COLUMN)fair(COLUMN)85(COLUMN)76 Toronoto(COLUMN)clear(COLUMN)64(COLUMN)55 Vancouver(COLUMN)cloudy(COLUMN)66(COLUMN)57 Veracruz(COLUMN)pt. cldy.(COLUMN)91(COLUMN)75 Winnipeg(COLUMN)pt. cldy.(COLUMN)48(COLUMN)45(END TABLE)