<TABLE> <S> <C>
<PAGE>
<ARTICLE> UT
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
STATEMENTS OF INCOME AND RETAINED EARNINGS, BALANCE SHEETS AND STATEMENTS OF
CASH FLOWS AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL
STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000
<CIK>0000092521
<NAME>SOUTHWESTERN PUBLIC SERVICE COMPANY
<S> <C>
<PERIOD-TYPE> 9-MOS
<FISCAL-YEAR-END> DEC-31-1999
<PERIOD-END> SEP-30-2000
<BOOK-VALUE> PER-BOOK
<TOTAL-NET-UTILITY-PLANT> 1,787,246
<OTHER-PROPERTY-AND-INVEST> 12,262
<TOTAL-CURRENT-ASSETS> 288,443
<TOTAL-DEFERRED-CHARGES> 22,938
<OTHER-ASSETS> 254,365
<TOTAL-ASSETS> 2,365,254
<COMMON> 0
<CAPITAL-SURPLUS-PAID-IN> 353,099
<RETAINED-EARNINGS> 423,381
<TOTAL-COMMON-STOCKHOLDERS-EQ> 776,480
100,000
0
<LONG-TERM-DEBT-NET> 226,502
<SHORT-TERM-NOTES> 0
<LONG-TERM-NOTES-PAYABLE> 0
<COMMERCIAL-PAPER-OBLIGATIONS> 654,768
<LONG-TERM-DEBT-CURRENT-PORT> 0
0
<CAPITAL-LEASE-OBLIGATIONS> 0
<LEASES-CURRENT> 0
<OTHER-ITEMS-CAPITAL-AND-LIAB> 607,504
<TOT-CAPITALIZATION-AND-LIAB> 2,365,254
<GROSS-OPERATING-REVENUE> 792,404
<INCOME-TAX-EXPENSE> 49,290
<OTHER-OPERATING-EXPENSES> 625,340
<TOTAL-OPERATING-EXPENSES> 625,340
<OPERATING-INCOME-LOSS> 167,064
<OTHER-INCOME-NET> (10,722)
<INCOME-BEFORE-INTEREST-EXPEN> 107,052
<TOTAL-INTEREST-EXPENSE> 47,219
<NET-INCOME> 59,833
0
<EARNINGS-AVAILABLE-FOR-COMM> 59,833
<COMMON-STOCK-DIVIDENDS> 44,736
<TOTAL-INTEREST-ON-BONDS> 41,331
<CASH-FLOW-OPERATIONS> 50,611
<EPS-BASIC> 0
<EPS-DILUTED> 0
</TABLE>
