NWN

nwn-2026022700017339980000073020falsefalse00017339982026-02-272026-02-270001733998nwn:NorthwestNaturalGasCompanyMember2026-02-272026-02-27

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

February 27, 2026 Date of Report (Date of earliest event reported)

NORTHWEST NATURAL HOLDING COMPANYNORTHWEST NATURAL GAS COMPANY

(Exact name of registrant as specified in its charter) (Exact name of registrant as specified in its charter) Commission file number 1-38681 Commission file number1-15973 Oregon82-4710680Oregon93-0256722 (State or other jurisdiction of incorporation or organization)(I.R.S. Employer Identification No.)(State or other jurisdiction of incorporation or organization)(I.R.S. Employer Identification No.)

250 S.W. Taylor Street250 S.W. Taylor Street Portland,Oregon97204 Portland,Oregon97204 (Address of principal executive offices)  (Zip Code)(Address of principal executive offices)  (Zip Code)

Registrant’s telephone number, including area code:(503)226-4211Registrant’s telephone number, including area code:(503)226-4211

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below): ☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐    Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐    Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐    Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: RegistrantTitle of each classTrading SymbolName of each exchange on which registered

Northwest Natural Holding CompanyCommon StockNWNNew York Stock Exchange Northwest Natural Gas CompanyNone

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Northwest Natural Holding CompanyEmerging growth company☐ Northwest Natural Gas CompanyEmerging growth company☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐

Item 2.02Results of Operation and Financial Condition

On February 27, 2026, Northwest Natural Holding Company (NW Holdings) issued a press release announcing its earnings for the quarter and year ended December 31, 2025. A copy of the press release is attached as Exhibit 99.1.

The information contained in this Item 2.02 and in the accompanying exhibit shall not be incorporated by reference into any filing of NW Holdings or Northwest Natural Gas Company (NW Natural), whether made before or after the date hereof, regardless of any general incorporation language in such filing, unless expressly incorporated by specific reference to such filing. The information in this Item 2.02, including the exhibit hereto, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended.

Forward-Looking Statements

This press release, and other presentations made by NW Holdings from time to time, may contain forward-looking statements within the meaning of the U.S. Private Securities Litigation Reform Act of 1995. Forward-looking statements can be identified by words such as "anticipates," "assumes," “continues,” “could,” "intends," "plans," "seeks," "believes," "estimates," "expects," "forecasts," "will" and similar references to future periods. Examples of forward-looking statements include, but are not limited to, statements regarding the following: plans, objectives, assumptions, estimates, expectations, forecasts, outlooks, timing, goals, strategies, commitments, future events, financial positions, financial performance, investments, valuations, timing and amount of capital expenditures, targeted capital structure, risks, risk profile, stability, acquisitions and timing, approval, completion and integration thereof, the likelihood and success associated with any transaction, strategic fit, utility system, technology and infrastructure investments, expected timing of notice to proceed, the initiation of construction, expected in service date and capital expenditure requirements for MX3, system modernization, reliability and resiliency, global, national and local economies, economic and GDP growth, customer and business growth, continued expansion of service territories,

nwn-2025110500017339980000073020falsefalse0001733998nwn:NorthwestNaturalGasCompanyMember2025-11-052025-11-0500017339982025-11-052025-11-05

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 8-K

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

November 5, 2025 Date of Report (Date of earliest event reported)

NORTHWEST NATURAL HOLDING COMPANYNORTHWEST NATURAL GAS COMPANY

(Exact name of registrant as specified in its charter) (Exact name of registrant as specified in its charter) Commission file number 1-38681 Commission file number 1-15973 Oregon82-4710680Oregon93-0256722 (State or other jurisdiction of incorporation)(I.R.S. Employer Identification No.)(State or other jurisdiction of incorporation or organization)(I.R.S. Employer Identification No.)

250 SW Taylor Street250 SW Taylor Street Portland,Oregon97204 Portland,Oregon97204 (Address of principal executive offices)  (Zip Code)(Address of principal executive offices)  (Zip Code)

Registrant’s telephone number, including area code:(503)226-4211Registrant’s telephone number, including area code:(503)226-4211

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below): ☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐    Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐    Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐    Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: RegistrantTitle of each classTrading SymbolName of each exchange on which registered

Northwest Natural Holding CompanyCommon StockNWNNew York Stock Exchange Northwest Natural Gas CompanyNone

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Northwest Natural Holding CompanyEmerging growth company☐ Northwest Natural Gas CompanyEmerging growth company☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐

Item 2.02Results of Operation and Financial Condition

On November 5, 2025, Northwest Natural Holding Company (NW Holdings) issued a press release announcing its earnings for the quarter ended September 30, 2025. A copy of the press release is attached as Exhibit 99.1.

The information contained in this Item 2.02 and in the accompanying exhibit shall not be incorporated by reference into any filing of NW Holdings or Northwest Natural Gas Company (NW Natural), whether made before or after the date hereof, regardless of any general incorporation language in such filing, unless expressly incorporated by specific reference to such filing. The information in this Item 2.02, including the exhibit hereto, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended.

Forward-Looking Statements

This press release, and other presentations made by NW Holdings from time to time, may contain forward-looking statements within the meaning of the U.S. Private Securities Litigation Reform Act of 1995. Forward-looking statements can be identified by words such as "anticipates," "assumes," “continues,” “could,” "intends," "plans," "seeks," "believes," "estimates," "expects," "forecasts," "will" and similar references to future periods. Examples of forward-looking statements include, but are not limited to, statements regarding the following: plans, objectives, assumptions, estimates, expectations, forecasts, outlooks, timing, goals, strategies, commitments, future events, financial positions, financial performance, investments, valuations, timing and amount of capital expenditures, targeted capital structure, risks, risk profile, stability, acquisitions and timing, approval, completion and integration thereof, the likelihood and success associated with any transaction, strategic fit, utility system, technology and infrastructure investments, system modernization, reliability and resiliency, global, national and local economies, economic and GDP growth, customer and business growth, continued expansion of service territories, rate base growth, customer backlog, growth opportunities, customer satisfaction ratings, weather, performance and service during weather events, customer rates or rate r

nwn-2025080500017339980000073020falsefalse0001733998nwn:NorthwestNaturalGasCompanyMember2025-08-052025-08-0500017339982025-08-052025-08-05

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 8-K

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

August 5, 2025 Date of Report (Date of earliest event reported)

NORTHWEST NATURAL HOLDING COMPANYNORTHWEST NATURAL GAS COMPANY

(Exact name of registrant as specified in its charter) (Exact name of registrant as specified in its charter) Commission file number 1-38681 Commission file number 1-15973 Oregon82-4710680Oregon93-0256722 (State or other jurisdiction of incorporation)(I.R.S. Employer Identification No.)(State or other jurisdiction of incorporation or organization)(I.R.S. Employer Identification No.)

250 SW Taylor Street250 SW Taylor Street Portland,Oregon97204 Portland,Oregon97204 (Address of principal executive offices)  (Zip Code)(Address of principal executive offices)  (Zip Code)

Registrant’s telephone number, including area code:(503)226-4211Registrant’s telephone number, including area code:(503)226-4211

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below): ☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐    Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐    Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐    Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: RegistrantTitle of each classTrading SymbolName of each exchange on which registered

Northwest Natural Holding CompanyCommon StockNWNNew York Stock Exchange Northwest Natural Gas CompanyNone

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Northwest Natural Holding CompanyEmerging growth company☐ Northwest Natural Gas CompanyEmerging growth company☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐

Item 2.02Results of Operation and Financial Condition

On August 5, 2025, Northwest Natural Holding Company (NW Holdings) issued a press release announcing its earnings for the quarter ended June 30, 2025. A copy of the press release is attached as Exhibit 99.1.

The information contained in this Item 2.02 and in the accompanying exhibit shall not be incorporated by reference into any filing of NW Holdings or Northwest Natural Gas Company (NW Natural), whether made before or after the date hereof, regardless of any general incorporation language in such filing, unless expressly incorporated by specific reference to such filing. The information in this Item 2.02, including the exhibit hereto, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended.

Forward-Looking Statements

This report, and other presentations made by NW Holdings from time to time, may contain forward-looking statements within the meaning of the U.S. Private Securities Litigation Reform Act of 1995. Forward-looking statements can be identified by words such as "anticipates," "assumes," “continues,” “could,” "intends," "plans," "seeks," "believes," "estimates," "expects," "forecasts," "will" and similar references to future periods. Examples of forward-looking statements include, but are not limited to, statements regarding the following: plans, objectives, assumptions, estimates, expectations, forecasts, outlooks, timing, goals, strategies, commitments, future events, financial positions, financial performance, investments, valuations, timing and amount of capital expenditures, targeted capital structure, risks, risk profile, stability, acquisitions and timing, approval, completion and integration thereof, the likelihood and success associated with any transaction, strategic fit, utility system, technology and infrastructure investments, system modernization, reliability and resiliency, global, national and local economies, economic and GDP growth, customer and business growth, continued expansion of service territories, rate base growth, customer backlog, growth opportunities, customer satisfaction ratings, weather, performance and service during weather events, customer rates or rate recovery and the