Exhibit 99.1

WGL Holdings, Inc. Reports First Quarter Fiscal Year 2014 Financial Results;

Affirms Fiscal Year 2014 Non-GAAP Guidance

Consolidated Results

WGL Holdings, Inc. (NYSE: WGL), the parent company of Washington Gas Light Company (Washington Gas) and other energy-related subsidiaries, today reported net income determined in accordance with generally accepted accounting principles in the United States of America (GAAP) for the quarter ended December 31, 2013, of $18.6 million, or $0.36 per share, compared to net income of $52.4 million, or $1.01 per share, reported for the quarter ended December 31, 2012.

Financial performance is also evaluated based on non-GAAP operating earnings (loss). Non-GAAP operating earnings (loss) adjusts for the effects of applying GAAP to certain transactions or classes of transactions that are not representative of the ongoing operating earnings of the company. Refer to “Use of Non-GAAP Operating Earnings (Loss)” and supporting reconciliations attached to this news release for a detailed discussion of management’s use of non-GAAP operating earnings, as well as reconciliations of net income determined in accordance with GAAP to non-GAAP operating earnings (loss) for both our consolidated and segment results.

For the quarter ended December 31, 2013, non-GAAP operating earnings were $51.4 million, or $0.99 per share, compared to non-GAAP operating earnings of $58.9 million, or $1.14 per share, for the same quarter of the prior fiscal year.

“I am pleased to announce first quarter non-GAAP results that exceeded our internal expectations and showed strong growth in earnings at our regulated utility,” said Terry McCallister, Chairman and Chief Executive Officer. “These results were driven both by higher revenues and lower O&M expenses. I am also pleased with our very strong operational performance as we maintained uninterrupted service to our customers during an extremely cold winter marked by several days of natural gas send out that were among the highest in our history.

“While volatile electricity costs in the PJM market continue to pressure the earnings of our retail energy-marketing business, the impact of the cold weather on natural gas spreads is expected to improve results at both our midstream energy services and utility segments and allow us to deliver annual results at the high end of our guidance.

“Additionally, our board of directors has approved an eight-cent increase in our dividend to an annual rate of $1.76 per share. This increase is consistent with our previously announced goal of maintaining a 5% dividend growth rate, and reflects our continued confidence in our ability to achieve our strategic goals and accelerate our underlying earnings growth rate. This increase marks the 38^th year of consecutive dividend increases and the 163^rd year that we have paid a dividend.”

First Quarter Results by Business Segment

Regulated Utility

For the quarter ended December 31, 2013, the regulated utility segment reported net income of $38.7 million, or $0.75 per share, compared to net income of $38.7 million, or $0.75 per share, reported for the same quarter of the prior fiscal year. After adjustments, non-GAAP operating earnings for the regulated utility segment were $50.4 million, or $0.97 per share, for the quarter ended December 31, 2013, an increase of $6.5 million, or $0.12 per share, over non-GAAP operating earnings of $43.9 million, or $0.85 per share, for the same quarter of the prior fiscal year. Higher non-GAAP operating earnings reflect higher revenues from customer growth, new base rates in Maryland, accelerated pipe replacement programs and favorable effects of changes in natural gas consumption patterns in the District of Columbia. Partially offsetting these favorable variances were higher property taxes.

Retail Energy-Marketing

For the quarter ended December 31, 2013, the retail energy-marketing segment reported net income of $3.3 million, or $0.06 per share, compared to net income of $13.0 million, or $0.25 per share, reported for the same quarter of the prior fiscal year. Non-GAAP operating earnings for the retail energy-marketing segment were $1.0 million, or $0.02 per share, for the quarter ended December 31, 2013, compared to non-GAAP operating earnings of $12.0 million, or $0.23 per share, for the same quarter of the prior fiscal year.

Non-GAAP operating earnings reflect lower realized electric margins primarily due to higher electric capacity charges and higher ancillary services charges from the regional power grid operator (PJM) versus the same quarter of the prior year. Natural gas realized margins decreased due to timing issues on gas supply costs partially offset by higher realized gas margins on portfolio optimization activity. The pattern of margin recognition that the retail energy-marketing segment realizes in a given quarter varies from year to year.

Commercial Energy Systems

For the quarter ended December 31, 2013, the commercial energy systems segment reported a net loss of $(0.1) million, compared to net income of $1.0 million, or $0.02 per share, for the same quarter of the prior fiscal year. The decrease in earnings is due to lower revenue from project work for government agency customers. There were no non-GAAP adjustments for this segment for any of the periods presented.

Midstream Energy Services Segment

For the quarter ended December 31, 2013, the midstream energy services segment reported a net loss of $(21.8) million, or $(0.42) per share, compared to net income of $1.3 million, or $0.02 per share, for the same period of the prior fiscal year. Non-GAAP operating earnings for the midstream energy services segment were $1.2 million, or $0.02 per share, compared to non-GAAP operating earnings of $3.5 million, or $0.07 per share for the same period of the prior fiscal year. Non-GAAP operating earnings for the year were lower than in the prior year principally due to unfavorable storage spreads partially offset by lower expenses.

Other Activities

For the quarter ended December 31, 2013, other activities reported a net loss of $(1.7) million, or $(0.03) per share, compared to a net loss of $(1.6) million, or $(0.03) per share, for the same quarter of the prior fiscal year. Non-GAAP operating losses for other activities were $(1.2) million, or $(0.02) per share, compared to non-GAAP operating losses of $(1.6) million, or $(0.03) per share, for the same period of the prior fiscal year.

The non-GAAP comparisons reflect the positive impact of tax sharing allocations partially offset by corporate branding initiative costs and our ongoing business development activities.

Earnings Outlook

We are affirming our non-GAAP consolidated earnings estimate for fiscal year 2014 in a range of $2.15 per share to $2.35 per share. In providing fiscal year 2014 earnings guidance, management is aware that there could be differences between what is reported earnings and estimated earnings for matters such as, but not limited to, unrealized mark-to-market positions for our energy-related derivatives. At this time, WGL management is not able to reasonably estimate the aggregate impact of these items on reported earnings and therefore is not able to provide a corresponding GAAP equivalent for its operating earnings guidance.

We assume no obligation to update this guidance. The absence of any statement by us in the future should not be presumed to represent an affirmation of this earnings guidance. For the assumptions underlying this guidance, please refer to the slides accompanying our webcast that will be posted to WGL’s website, www.wglholdings.com.

Other Information

We will hold a conference call at 10:30 a.m. Eastern Time on February 6, 2014, to discuss our first quarter fiscal year 2014 financial results. The live conference call will be available to the public via a link located on WGL’s website, www.wglholdings.com. To hear the live webcast, click on the “Webcast” link located on the home page of the referenced site. The webcast and related slides will be archived on WGL’s website through March 6, 2014.

Headquartered in Washington, D.C., WGL is a leading source for clean and efficient energy solutions. Through our affiliates and strategic relationships, the Company offers a diverse set of energy sources including natural gas, wind and solar as well as a range of energy solutions – generation, storage, transportation, distribution, supply and efficiency – which serve customers in more than 25 states. WGL has five operating segments: Washington Gas Light Company, a regulated natural gas utility serving approximately 1.1 million customers in the metropolitan Washington, D.C., area; Washington Gas Energy Services, Inc., one of the largest natural gas, electricity and green energy suppliers in the Mid-Atlantic; Washington Gas Energy Systems, Inc., a distributed generation and energy efficiency business, offering solar, fuel cell, combined heat and power, and other technologies across the United States; WGL Midstream, a midstream energy services business, investing in and optimizing natural gas pipelines and storage facilities in the Midwest and Eastern United States; and Hampshire Gas, a natural gas storage business which owns and operates facilities in and around Hampshire County, West Virginia. As product and service innovation are critical for value creation and sustaining growth, we are continuously increasing our assets and investments in targeted clean energy sectors. This strategy supports WGL’s core business, as well as provides opportunity for growth through partnerships and investments. WGL’s diversity is its strength. We are dedicated to the sustainability of our business, the customers and communities we serve, and the environment. To learn more, visit www.wglholdings.com.

Unless otherwise noted, earnings per share amounts are presented on a diluted basis, and are based on weighted average common and common equivalent shares outstanding.

Please see the attached comparative statements for additional information on our operating results. Also attached to this news release are reconciliations of net income determined in accordance with GAAP to non-GAAP operating earnings (loss) for both our consolidated and segment results, as well as reconciliations of our GAAP earnings guidance to our non-GAAP earnings guidance.

Forward-Looking Statements

This news release and other statements by us include forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 with respect to the outlook for earnings, revenues and other future financial business performance or strategies and expectations. Forward-looking statements are typically identified by words such as, but not limited to, “estimates,” “expects,” “anticipates,” “intends,” “believes,” “plans,” and similar expressions, or future or conditional verbs such as “will,” “should,” “would,” and “could.” Although we believe such forward-looking statements are based on reasonable assumptions, we cannot give assurance that every objective will be achieved. Forward-looking statements speak only as of today, and we assume no duty to update them. Factors that could cause actual results to differ materially from those expressed or implied include, but are not limited to, general economic conditions and the factors discussed under the “Risk Factors” heading in our most recent annual report on Form 10-K and other documents we have filed with, or furnished to, the U.S. Securities and Exchange Commission.

WGL Holdings, Inc.

Consolidated Balance Sheets

(Unaudited)

WGL Holdings, Inc.

Consolidated Statements of Income

(Unaudited)

WGL Holdings, Inc.

Consolidated Financial and Operating Statistics

(Unaudited)

WGL HOLDINGS, INC.

USE OF NON-GAAP OPERATING EARNINGS (LOSS)

(Unaudited)

The attached reconciliations are provided to clearly identify adjustments made to net income calculated in accordance with GAAP to derive non-GAAP operating earnings (loss). Management believes non-GAAP operating earnings (loss) provides a more meaningful representation of our earnings from ongoing operations by adjusting for the effects of: (i) unrealized mark-to-market gains and losses from energy-related derivatives for our regulated utility and retail marketing segments; (ii) unrealized gains (losses) on certain derivatives for the long-term purchase of natural gas for the midstream energy services segment; (iii) certain gains and losses associated with optimizing the utility segment’s capacity assets; (iv) changes in the measured value of our inventory for our midstream energy services segment; (v) for our regulated utility segment, the estimated financial effects of warmer-than-normal/colder-than-normal weather as measured consistent with our jurisdictional tariffs, to the extent the effects are not offset by weather protection mechanisms; (vi) incremental legal and consulting costs associated with business development activities; and (vii) certain unusual transactions. This presentation facilitates analysis by providing a consistent and comparable measure to help management, investors and analysts better understand and evaluate our operating results and performance trends, to forecast future results and assist in analyzing period-to-period comparisons. Additionally, we use this non-GAAP measure to report to the board of directors and to evaluate management’s performance. The economic substance underlying our adjustments to calculate non-GAAP operating earnings (loss) is as follows:

With the exception of certain transactions related to the optimization of system capacity assets as discussed below, when these derivatives settle, the realized economic impact is reflected in our non-GAAP operating results, as we are only removing interim unrealized mark-to-market amounts.

We also exclude valuation adjustments to the carrying value of non-system natural gas storage inventory in our regulated utility segment. This inventory is held solely to support asset optimization transactions. Valuation adjustments to reflect lower-of-cost or market under current accounting standards may not be representative of the margins that will be realized and shared with our utility ratepayers. Non-GAAP earnings reflect actual margins realized based on the unadjusted historical cost in storage when inventory is withdrawn and sold.

WGL HOLDINGS, INC.

USE OF NON-GAAP OPERATING EARNINGS (LOSS)

(Unaudited)

There are limits in using non-GAAP operating earnings (loss) to analyze our results, as they are not prepared in accordance with GAAP and may be different from non-GAAP financial measures used by other companies. In addition, using non-GAAP operating earnings (loss) per share to analyze our earnings may have limited value as it excludes certain items that may have a material impact on our reported financial results. We compensate for these limitations by providing investors with the attached reconciliations to net income, the most directly comparable GAAP financial measure.

WGL HOLDINGS, INC. (Consolidating by Segment)

RECONCILIATION OF GAAP NET INCOME (LOSS) TO

NON-GAAP OPERATING EARNINGS (LOSS)

(Unaudited)

  (Footnote references are described on the following page.)

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