Source: Wal-Mart.

Shares of Wal-Mart Stores (NYSE:WMT) opened 3.1% lower this morning, following the release of results for the first quarter of fiscal year 2015, which showed a negative impact from bad weather.

"Like other retailers in the United States, the unseasonably cold and disruptive weather negatively impacted U.S. sales and drove operating expenses higher than expected," said CEO Doug McMillon in the company's press release.

Analysts were looking for earnings of $1.15 per share on $116 billion in total revenue. The company reported GAAP earnings of $1.10 per diluted share and revenue of $114 billion.

The company said severe American winter weather at the start of the quarter reduced earnings by $0.03 per share. On the top line, negative currency exchange fluctuations lowered Wal-Mart's reported sales by approximately $1.6 billion.

Looking ahead, Wal-Mart expects second-quarter earnings of roughly $1.20 per share, down from $1.24 per share in the second quarter of fiscal 2014. The current analyst view points to $1.28 per share. The soft guidance assumes increased investments in e-commerce programs and Sam'sClub membership drives, as well as increased health care costs in the domestic market.

Wal-Mart's small-footprint Neighborhood Markets concept saw healthy growth, including 5% higher comparable-stores sales. Sales in this segment have doubled over the last two years, as the company rolls out large numbers of this store format amid positive comps.

"Walmart's underlying business is solid, and I'm confident in our long-term strategies," said McMillon in a prepared statement. "We'll continue to invest in price and enhance our service to improve sales. We remain focused on growth across the enterprise, especially in small formats like Neighborhood Market in the U.S."

By 10:15 a.m., shares were down almost 2% from yesterday's closing price.

Anders Bylund has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days.

We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.