IDACORP's 2021 first quarter earnings per diluted share were $0.89, an increase of $0.15 per share from last year's first quarter.
Today, we also affirmed our full year 2021 IDACORP earnings guidance to be in the range of $4.60 to $4.80 per diluted share, with our expectation that Idaho Power will not need to utilize in 2021 any of the additional tax credits that are available to support earnings in Idaho under its regulatory settlement stipulation.
In March alone, we saw an annualized customer growth rate of 3.5%.
Unemployment within Idaho Power's service area is now down to 3.7%, remaining well below the 6% rate reported at the national level, and total employment in our service area declined a modest 0.3% since March of last year.
The Moody's forecast now calls for growth of 8% in 2021, 8.1% in 2022 and continued strong growth of 6.8% in 2023.
Last quarter, we stated Idaho Power does not plan to file a general rate case in Idaho or Oregon in the next 12 months.
That remains true today as we look at the next 12 months.
As a reminder, we expect to spend approximately $47 million in incremental O&M and $35 million in incremental capital expenses for wildfire-related infrastructure work over the next five years.
Altogether, IDACORP's first quarter 2021 net income was higher by $7.3 million.
On the table of quarter-over-quarter changes, you'll see customer growth added $3.7 million to operating income.
Lower usage per commercial customer down 2%, partly due to COVID-19 impact, was largely offset by higher residential usage due to colder weather this year versus last.
The net result was a relatively modest $1.3 million decrease in overall usage per customer.
The next change on the table shows that transmission wheeling-related revenues increased $4.1 million.
This was partly due to a 20% increase in wheeling volumes as well as a 10% increase in Idaho Power's open access transmission tariff rate last October to reflect higher transmission costs.
Next on the table, other operating and maintenance expenses decreased by $4.2 million.
Finally, our higher pre-tax earnings led to an increase in income tax expense of $1.5 million this quarter.
The changes collectively resulted in an increase to Idaho Power's net income of $7.6 million.
Cash flows from operations were about $50 million higher than last year's first quarter.
We continue to expect IDACORP's 2021 earnings to be in the range of $4.60 to $4.80 per diluted share as we assume normal weather and operating conditions for the remaining nine months of the year.
Our expected full year O&M expense guidance remains in the range of the $345 million to $355 million, so we're off to a good start.
We also affirm our capital expenditures forecast for this year, which we increased a bit in February to the range of $320 million to $330 million.
Our expectation of hydro generation has softened somewhat given the conditions Lisa presented earlier and is now expected to be in the range of 5.5 million to 7.5 million megawatt hours.

Summary:
IDACORP's 2021 first quarter earnings per diluted share were $0.89, an increase of $0.15 per share from last year's first quarter.
Today, we also affirmed our full year 2021 IDACORP earnings guidance to be in the range of $4.60 to $4.80 per diluted share, with our expectation that Idaho Power will not need to utilize in 2021 any of the additional tax credits that are available to support earnings in Idaho under its regulatory settlement stipulation.
We continue to expect IDACORP's 2021 earnings to be in the range of $4.60 to $4.80 per diluted share as we assume normal weather and operating conditions for the remaining nine months of the year.