UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (mark one) QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2020 OR TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 1-10499 NORTHWESTERN CORP (Exact name of registrant as specified in its charter) | | | (State or other jurisdiction of incorporation or ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (mark one) QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 1-10499 NORTHWESTERN CORP (Exact name of registrant as specified in its charter) | | Delaware | | 46-0172280 | | --- | --- | --- | --- | | | (State or other jurisdiction of | | (I.R.S. Employer | | | incorporation or organization) | | Identification No.) | | 3010 W. 69th S ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2019 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 1-10499 NORTHWESTERN CORP (Exact name of registrant as specified in its charter) | | Delaware | | 46-0172280 | | --- | --- | --- | --- | ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (mark one) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2019 OR TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 1-10499 NORTHWESTERN CORP (Exact name of registrant as specified in its charter) | | Delaware | | 46-0172280 | | --- | --- | --- ...

For the quarterly period ended June 30, 2019 UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (mark OR one) QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 NORTHWESTERN CORP (Exact name of registrant as specified in its charter) Delaware 46-0172280 (State or other jurisdiction of incorporation or organization) (I.R.S. Employer Identification No.) 3010 W. 69th Street Sioux Falls South Dakota 57108 (Address of principal executive offices ...

Financial Performance - Consolidated net income for Q1 2019 was $72.8 million, an increase of 24.4% from $58.5 million in Q1 2018, primarily driven by higher retail volumes and revenue growth [104]. - Total operating revenues increased to $384.2 million in Q1 2019 from $341.5 million in Q1 2018, reflecting a growth of 12.4% [123]. - Gross margin for Q1 2019 was $268.5 million, up 9.4% from $245.4 million in Q1 2018, with electric gross margin increasing by 8.3% and natural gas gross margin increasing by 12.6% [124]. - Consolidated operating income for Q1 2019 increased to $97.0 million from $84.5 million in Q1 2018, driven by higher gross margin despite increased operating expenses [130]. - Total retail electric revenues for Q1 2019 were $273.0 million, a 14.6% increase from $238.3 million in Q1 2018, with retail revenues specifically rising by 4.1% [137]. - Retail natural gas revenues for Q1 2019 were $106.8 million, a 7.6% increase from $99.3 million in Q1 2018, contributing to total revenues of $111.2 million [142]. - Consolidated interest expense for Q1 2019 was $23.8 million, up from $23.0 million in Q1 2018, primarily due to higher borrowings [131]. - Property and other taxes increased to $44.8 million in Q1 2019 from $42.8 million in Q1 2018, attributed to plant additions and higher property valuations [129]. - Depreciation and depletion expense rose to $45.6 million in Q1 2019 from $43.8 million in Q1 2018, mainly due to plant additions [130]. - Effective tax rate for Q1 2019 was 2.1%, down from 3.2% in Q1 2018, with an expected range of 0% - 5% for the full year [133]. - Consolidated other income improved to $1.1 million in Q1 2019 from a loss of $1.1 million in Q1 2018, driven by an increase in the value of deferred shares [132]. - Gross margin impacting net income rose by $7.7 million, primarily due to increased retail volumes and the impact of the Tax Cuts and Jobs Act [144]. Rate Increases and Regulatory Actions - The company filed for an electric rate increase of approximately $34.9 million, representing a 6.6% increase in annual base revenues, based on a return on equity of 10.65% [108]. - An interim rate increase of approximately $10.5 million was approved by the MPSC effective April 1, 2019, with a final order expected after a hearing scheduled for May 13, 2019 [109]. Operational Challenges and Strategies - The Montana Resource Plan indicates a forecasted energy portfolio shortfall of 725 MW by 2025, prompting plans to solicit competitive proposals for peaking capacity [113]. - The company is currently 630 MW short of peak needs, which it procures from the market, and expects to address this through future solicitations [113]. - The company is exploring alternative coal supply sources due to the bankruptcy of Western Energy Company, which may result in higher costs [116]. - The company aims to enhance grid reliability and safety through infrastructure investments, including automation in distribution and substations [102]. - The company experienced colder weather in 2019, with Montana being 14% colder than 2018, which contributed to increased retail volumes [143]. Cash Flow and Liquidity - Cash provided by operating activities decreased to $111.4 million in Q1 2019 from $173.0 million in Q1 2018, a decline of about 35.6% [159]. - Cash used in investing activities increased by approximately $13.6 million, totaling $65.6 million in Q1 2019 compared to $52.0 million in Q1 2018 [160]. - Cash used in financing activities decreased to $50.1 million in Q1 2019 from $122.1 million in Q1 2018, reflecting a significant reduction in net repayments of commercial paper [161]. - As of March 31, 2019, total net liquidity was approximately $142.8 million, including $4.0 million in cash and $138.8 million in revolving credit facility availability [152]. - As of March 31, 2019, the company had under collected supply costs by approximately $26.1 million, impacting cash flows from operations [156]. Debt and Financial Obligations - The company plans to maintain a debt to total capital ratio of 50-55% and a long-term dividend payout ratio of 60-70% of earnings per share [150]. - Total long-term debt amounts to $2,092,637,000, with a significant portion of $1,822,637,000 due thereafter [163]. - Estimated pension and other postretirement obligations total $63,235,000, with annual contributions expected to exceed minimum funding requirements [164]. - The company has contractual obligations related to qualifying facilities (QFs) estimated at approximately $691,000,000, with recoverable costs totaling about $552,500,000 [165]. - Total commitments amount to $6,380,626,000, with a significant portion of $4,607,444,000 due thereafter [166]. - The company has approximately $286,000,000 in borrowings under revolving credit facilities, with a 1.0% increase in interest rates potentially raising annual interest expenses by about $2,900,000 [173]. - The average interest rate on outstanding balances for revolving credit facilities is assumed to be 3.74% [166]. - Contractual interest payments on debt total $1,493,321,000, with varying rates based on the type of facility [166]. Risk Management - The company employs market purchases and sales, including forward contracts, to manage commodity price volatility risk [175]. - Counterparty credit risk is managed through policies that limit transactions to high-quality counterparties and require letters of credit or prepayment terms [176]. - The company has entered into various purchase commitments for energy supply, which range from one to 25 years [166].

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-K (Mark One) x ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2018 OR o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 1-10499 NORTHWESTERN CORPORATION (Exact name of registrant as specified in its charter) (State or other jurisdiction of incorporation or ...